<PAGE>

                                                                     EXHIBIT 4.5

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AS
AMENDED, OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE SOLD, OFFERED FOR SALE,
PLEDGED, OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
RELATED THERETO OR AN OPINION OF COUNSEL (WHICH MAY BE COMPANY COUNSEL)
REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE SECURITIES
LAWS.

                               WARRANT AGREEMENT

             To Purchase Shares of the Series C Preferred Stock of

                              TIOGA SYSTEMS, INC.

              Dated as of October 27, 1998 (the "Effective Date")

          WHEREAS, TIOGA SYSTEMS, INC., a Delaware corporation (the "Company")
has entered into a Master Lease Agreement dated as of October 27, 1998,
Equipment Schedule No. VL-1 and VL-2 dated as of October 27, 1998, and related
Summary Equipment Schedules (collectively, the "Leases") with Comdisco, Inc., a
Delaware corporation (the "Warrantholder"); and

          WHEREAS, the Company desires to grant to Warrantholder, in
consideration for such Leases, the right to purchase shares of its Series C
Preferred Stock;

          NOW, THEREFORE, in consideration of the Warrantholder executing and
delivering such Leases and in consideration of mutual covenants and agreements
contained herein, the Company and Warrantholder agree as follows:

1.        GRANT OF THE RIGHT TO PURCHASE PREFERRED STOCK.
          ----------------------------------------------

          The Company hereby grants to the Warrantholder, and the Warrantholder
is entitled, upon the terms and subject to the conditions hereinafter set forth,
to subscribe to and purchase, from the Company, that number of fully paid and
non-assessable shares of the Company's Series C Preferred Stock ("Preferred
Stock") equal to $500,000 multiplied by 3% divided by a purchase price equal to
the average of $0.68747 and the price per share of the next round of financing
which shall be defined as an initial public offering, acquisition or merger of
the Company (the "Next Round") (the "Exercise Price").

          In the event that the Next Round has not occurred within 24 months
from the date hereof, the price to be used for the price per share of the Next
Round shall be based on a fairness opinion of valuation of the Company by an
investment banking firm to be mutually agreed upon by the Company and
Warrantholder and the Company shall pay for such opinion.  In the event the
Company and Warrantholder can not mutually agree on an investment banking firm
to provide such fairness opinion of valuation, then each party shall select an
investment bank of their choice (and at their own expense) and the valuation
shall be the numeric average of the valuations received from the investment
banking firms.

          The number and purchase price of such shares are subject to adjustment
as provided in Section 8 hereof.

2.        TERM OF THE WARRANT AGREEMENT.
          -----------------------------

          Except as otherwise provided for herein, the term of this Warrant
Agreement and the right to purchase Preferred Stock as granted herein shall
commence upon the close of the Next Round and shall be exercisable for a period
of (i) seven (7) years or (ii) three (3) years from the effective date of the
Company's initial public offering, whichever is longer.

          Notwithstanding the term of this Warrant Agreement as set forth above,
the right to purchase Preferred Stock as granted shall expire, if not previously
exercised, immediately upon the closing of the issuance and sale of shares of
Common Stock of the Company in the Company's first public offering of securities
for its own account pursuant to an effective registration statement under the
Securities Act of 1933, as amended (the "Initial Public Offering"), provided
that the Preferred stock issuable to Warrantholder upon exercise hereof shall be
included in such registration statement, and provided further that the
underwriters so request that the Warrantholder exercise at that time.

                                      -1-
<PAGE>

          The Company shall notify the Warrantholder if the Initial Public
Offering is proposed within a reasonable period of time prior to the filing of a
registration statement and if the Company fails to deliver such written notice
within a reasonable period of time, anything to the contrary in this Warrant
Agreement notwithstanding, the rights to purchase will not expire until ten (10)
business days after the Company delivers such notice to the Warrantholder.  Such
notice shall also contain such details of the proposed Initial Public Offering
as are reasonable in the circumstances and notice that this Warrant Agreement is
expected to expire upon closing thereof. If such closing does not take place,
the Company shall promptly notify the Warrantholder that such proposed
transaction has been terminated.  Anything to the contrary in this Warrant
Agreement notwithstanding, the Warrantholder may rescind any exercise of its
purchase rights promptly after such notice of termination of the proposed
transaction if the exercise of warrants occurred after the Company notified the
Warrantholder that the Initial Public Offering was proposed or if the exercise
were otherwise precipitated by such proposed Initial Public Offering.  In the
event of such rescission, the Warrants will continue to be exercisable on the
same terms and conditions.

3.        EXERCISE OF THE PURCHASE RIGHTS.
          -------------------------------

          The purchase rights set forth in this Warrant Agreement are
exercisable by the Warrantholder, in whole or in part, at any time, or from time
to time, prior to the expiration of the term set forth in Section 2 above, by
tendering to the Company at its principal office a notice of exercise in the
form attached hereto as Exhibit I (the "Notice of Exercise"), duly completed and
executed.  Promptly upon receipt of the Notice of Exercise and the payment of
the purchase price in accordance with the terms set forth below, and in no event
later than twenty-one (21) days thereafter, the Company shall issue to the
Warrantholder a certificate for the number of shares of Preferred Stock
purchased and shall execute the acknowledgment of exercise in the form attached
hereto as Exhibit II (the "Acknowledgment of Exercise") indicating the number of
shares which remain subject to future purchases, if any.

          The Exercise Price may be paid at the Warrantholder's election either
(i) by cash or check, or (ii) by surrender of Warrants ("Net Issuance") as
determined below.  If the Warrantholder elects the Net Issuance method, the
Company will issue Preferred Stock in accordance with the following formula:

                         X = Y(A-B)
                             ------
                                 A

          Where:  X =    the number of shares of Preferred Stock to be issued to
                         the Warrantholder.

                         Y =  the number of shares of Preferred Stock requested
                              to be exercised under this Warrant Agreement.

                         A =  the fair market value of one (1) share of
                              Preferred Stock.

                         B =  the Exercise Price.

          For purposes of the above calculation, current fair market value of
Preferred Stock shall mean with respect to each share of Preferred Stock:

                    (i)  if the exercise is in connection with an initial public
     offering of the Company's Common Stock, and if the Company's Registration
     Statement relating to such public offering has been declared effective by
     the SEC, then the fair market value per share shall be the product of (x)
     the initial "Price to Public" specified in the final prospectus with
     respect to the offering and (y) the number of shares of Common Stock into
     which each share of Preferred Stock is convertible at the time of such
     exercise;

                    (ii) if this Warrant is exercised after, and not in
     connection with the Company's initial public offering,and:

                         (a) if traded on a securities exchange, the fair market
          value shall be deemed to be the product of (x) the average of the
          closing prices over a twenty-one (21 ) day period ending three days
          before the day the current fair market value of the securities is
          being determined and (y) the number of shares of Common Stock into
          which each share of Preferred Stock is convertible at the time of such
          exercise; or

                         (b) if actively traded over-the-counter, the fair
          market value shall be deemed to be the product of (x) the average of
          the closing bid and asked prices quoted on the NASDAQ system

                                      -2-
<PAGE>

          (or similar system) over the twenty-one (21) day period ending three
          days before the day the current fair market value of the securities is
          being determined and (y) the number of shares of Common Stock into
          which each share of Preferred Stock is convertible at the time of such
          exercise;

          (iii)  if at any time the Common Stock is not listed on any securities
     exchange or quoted in the NASDAQ System or the over-the-counter market, the
     current fair market value of Preferred Stock shall be the product of (x)
     the highest price per share which the Company could obtain from a willing
     buyer (not a current employee or director) for shares of Common Stock sold
     by the Company, from authorized but unissued shares, as determined in good
     faith by its Board of Directors and (y) the number of shares of Common
     Stock into which each share of Preferred Stock is convertible at the time
     of such exercise, unless the Company shall become subject to a merger,
     acquisition or other consolidation pursuant to which the Company is not the
     surviving party, in which case the fair market value of Preferred Stock
     shall be deemed to be the value received by the holders of the Company's
     Preferred Stock on a common equivalent basis pursuant to such merger or
     acquisition.

     Upon partial exercise by either cash or Net Issuance, the Company shall
promptly issue an amended Warrant Agreement representing the remaining number of
shares purchasable hereunder. All other terms and conditions of such amended
Warrant Agreement shall be identical to those contained herein, including, but
not limited to the Effective Date hereof.

4.   RESERVATION OF SHARES.
     ----------------------

     (a) Authorization and Reservation of Shares. During the term of this
         ---------------------------------------
Warrant Agreement, the Company will at all times have authorized and reserved a
sufficient number of shares of its Preferred Stock to provide for the exercise
of the rights to purchase Preferred Stock as provided for herein.

     (b) Registration or Listing. If any shares of Preferred Stock required to
         -----------------------
be reserved hereunder require registration with or approval of any governmental
authority under any Federal or State law (other than any registration under the
Securities Act of 1933, as amended ("1933 Act"), as then in effect, or any
similar Federal statute then enforced, or any state securities law, required by
reason of any transfer involved in such conversion), or listing on any domestic
securities exchange, before such shares may be issued upon conversion, the
Company will, at its expense and as expeditiously as possible, use its best
efforts to cause such shares to be duly registered, listed or approved for
listing on such domestic securities exchange, as the case may be.

5.   NO FRACTIONAL SHARES OR SCRIP.
     ------------------------------

     No fractional shares or scrip representing fractional shares shall be
issued upon the exercise of the Warrant, but in lieu of such fractional shares
the Company shall make a cash payment therefor upon the basis of the Exercise
Price then in effect.

6.   NO RIGHTS AS SHAREHOLDER.
     -------------------------

     This Warrant Agreement does not entitle the Warrantholder to any voting
rights or other rights as a shareholder of the Company prior to the exercise of
the Warrant.

7.   WARRANTHOLDER REGISTRY.
     -----------------------

     The Company shall maintain a registry showing the name and address of the
registered holder of this Warrant Agreement.

8.   ADJUSTMENT RIGHTS.
     ------------------

     The purchase price per share and the number of shares of Preferred Stock
purchasable hereunder are subject to adjustment, as follows:

     (a) Merger and Sale of Assets.  If at any time there shall be a capital
         -------------------------
reorganization of the shares of the Company's stock (other than a combination,
reclassification, exchange or subdivision of shares otherwise provided for
herein), or a merger or consolidation of the Company with or into another
corporation whether or not the Company is the surviving corporation, or the sale
of all or substantially all of the Company's properties and assets to any other
person (hereinafter referred to as a "Merger Event"), then, as a part of such
Merger Event, lawful provision

                                      -3-
<PAGE>

shall be made so that the Warrantholder shall thereafter be entitled to receive,
upon exercise of the Warrant, the number of shares of preferred stock or other
securities of the successor corporation resulting from such Merger Event,
equivalent in value to that which would have been issuable if Warrantholder had
exercised this Warrant immediately prior to the Merger Event. In any such case,
appropriate adjustment (as determined in good faith by the Company's Board of
Directors) shall be made in the application of the provisions of this Warrant
Agreement with respect to the rights and interest of the Warrantholder after the
Merger Event to the end that the provisions of this Warrant Agreement (including
adjustments of the Exercise Price and number of shares of Preferred Stock
purchasable) shall be applicable to the greatest extent possible.

     (b) Reclassification of Shares. If the Company at any time shall, by
         --------------------------
combination, reclassification, exchange or subdivision of securities or
otherwise, change any of the securities as to which purchase rights under this
Warrant Agreement exist into the same or a different number of securities of any
other class or classes, this Warrant Agreement shall thereafter represent the
right to acquire such number and kind of securities as would have been issuable
as the result of such change with respect to the securities which were subject
to the purchase rights under this Warrant Agreement immediately prior to such
combination, reclassification, exchange, subdivision or other change.

     (c) Subdivision or Combination of Shares.  If the Company at any time shall
         ------------------------------------
combine or subdivide its Preferred Stock, the Exercise Price shall be
proportionately decreased in the case of a subdivision, or proportionately
increased in the case of a combination.

     (d) Stock Dividends. If the Company at any time shall pay a dividend
         ---------------
payable in, or make any other distribution (except any distribution specifically
provided for in the foregoing subsections (a) or (b)) of the Company's stock,
then the Exercise Price shall be adjusted, from and after the record date of
such dividend or distribution, to that price determined by multiplying the
Exercise Price in effect immediately prior to such record date by a fraction (i)
the numerator of which shall be the total number of all shares of the Company's
stock outstanding immediately prior to such dividend or distribution, and (ii)
the denominator of which shall be the total number of all shares of the
Company's stock outstanding immediately after such dividend or distribution. The
Warrantholder shall thereafter be entitled to purchase, at the Exercise Price
resulting from such adjustment, the number of shares of Preferred Stock
(calculated to the nearest whole share) obtained by multiplying the Exercise
Price in effect immediately prior to such adjustment by the number of shares of
Preferred Stock issuable upon the exercise hereof immediately prior to such
adjustment and dividing the product thereof by the Exercise Price resulting from
such adjustment.

     (e) Right to Purchase Additional Stock. If, the Warrantholder's total cost
         ----------------------------------
of equipment leased pursuant to the Leases exceeds $500,000, Warrantholder shall
have the right to purchase from the Company, at the Exercise Price (adjusted as
set forth herein), an additional number of shares, which number shall be
determined by (i) multiplying the amount by which the Warrantholder's total
equipment cost exceeds $500,000 by 3%, and (ii) dividing the product thereof by
the Exercise Price per share referenced above.

     (f) Antidilution Rights. Additional antidilution rights applicable to the
         -------------------
Preferred Stock purchasable hereunder are as set forth in the Company's
Certificate of Incorporation, as amended through the Effective Date, a true and
complete copy of which is attached hereto as Exhibit __ (the "Charter"). The
Company shall promptly provide the Warrantholder with any restatement,
amendment, modification or waiver of the Charter. The Company shall provide
Warrantholder with prior written notice of any issuance of its stock or other
equity security to occur after the Effective Date of this Warrant, which notice
shall include (a) the price at which such stock or security is to be sold, (b)
the number of shares to be issued, and (c) such other information as necessary
for Warrantholder to determine if a dilutive event has occurred.

     (g) Notice of Adjustments. If: (i) the Company shall declare any dividend
         ---------------------
or distribution upon its stock, whether in cash, property, stock or other
securities; (ii) the Company shall offer for subscription prorata to the holders
of any class of its Preferred or other convertible stock any additional shares
of stock of any class or other rights; (iii) there shall be any Merger Event;
(iv) there shall be an initial public offering; or (v) there shall be any
voluntary dissolution, liquidation or winding up of the Company; then, in
connection with each such event, the Company shall send to the Warrantholder:
(A) at least twenty (20) days' prior written notice of the date on which the
books of the Company shall close or a record shall be taken for such dividend,
distribution, subscription rights (specifying the date on which the holders of
Preferred Stock shall be entitled thereto) or for determining rights to vote in
cespect of such Merger Event, dissolution, liquidation or winding up; (B) in the
case of any such Merger Event, dissolution, liquidation or winding up, at least
twenty (20) days' prior written notice of the date when the same shall take
place (and specifying the date on which the holders of Preferred Stock shall be
entitled to exchange their Preferred Stock for securities or other property
deliverable upon such Merger Event, dissolution, liquidation or

                                      -4-
<PAGE>

     winding up); and (C) in the case of a public offering, the Company
shall give the Warrantholder at least twenty (20) days written notice prior to
the effective date thereof.

     Each such written notice shall set forth, in reasonable detail, (i) the
event requiring the adjustment, (ii) the amount of the adjustment, (iii) the
method by which such adjustment was calculated, (iv) the Exercise Price, and (v)
the number of shares subject to purchase hereunder after giving effect to such
adjustment, and shall be given by first class mail, postage prepaid, addressed
to the Warrantholder, at the address as shown on the books of the Company.

     (i) Timely Notice.  Failure to timely provide such notice required by
         -------------
subsection (g) above shall entitle Warrantholder to retain the fit of the
applicable notice period notwithstanding anything to the contrary contained in
any insufficient notice received by Warrantholder. The notice period shall begin
on the date Warrantholder actually receives a written notice containing all the
information specified above.

9.   REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE COMPANY.
     ---------------------------------------------------------

     (a) Reservation of Preferred Stock.  The Preferred Stock issuable upon
         ------------------------------
exercise of the Warrantholder's rights will be, upon the Effective Date, duly
and validly reserved and, when issued in accordance with the provisions of this
Warrant Agreement, will be validly issued, fully paid and non-assessable, and
will be free of any taxes, liens, charges or encumbrances of any nature
whatsoever; provided, however, that the Preferred Stock issuable pursuant to
this Warrant Agreement may be subject to restrictions on transfer under state
and/or Federal securities laws.  The Company has made available to the
Warrantholder true, correct and complete copies of its Charter and Bylaws, as
amended.  The issuance of certificates for shares of Preferred Stock upon
exercise of the Warrant Agreement shall be Made without charge to the
Warrantholder for any issuance tax in respect thereof, or other cost incurred by
the Company in connection with such exercise and the related issuance of shares
of Preferred Stock.  The Company shall not be required to pay any tax which may
be payable in respect of any transfer involved and the issuance and delivery of
any certificate in a name other than that of the Warrantholder.

     (b) Due Authority. The execution and delivery by the Company of this
         -------------
Warrant Agreement and the performance of all obligations of the Company
hereunder, including the issuance to Warrantholder of the right to acquire the
shares of Preferred Stock, have been duly authorized by all necessary corporate
action on the part of the Company, and the Leases and this Warrant Agreement are
not inconsistent with the Company's Charter or Bylaws, do not contravene any law
or governmental rule, regulation or order applicable to it, do not and will not
contravene any provision of, or constitute a default under, any indenture,
mortgage, contract or other instrument to which it is a party or by which it is
bound, and the Leases and this Warrant Agreement constitute legal, valid and
binding agreements of the Company, enforceable in accordance with their
respective terms.

     (c) Consents and Approvals. No consent or approval of, giving of notice to,
         ----------------------
registration with, or taking of any other action in respect of any state,
Federal or other governmental authority or agency is required with respect to
the execution, delivery and performance by the Company of its obligations under
this Warrant Agreement, except for the filing of notices pursuant to Regulation
D under the 1933 Act and any filing required by applicable state securities law,
which filings will be effective by the time required thereby.

     (d) Issued Securities.  All issued and outstanding shares of Common Stock,
         -----------------
Preferred Stock or any other securities of the Company have been duly authorized
and validly issued and are fully paid and nonassessable.  All outstanding shares
of Common Stock, Preferred Stock and any other securities were issued in full
compliance with all Federal and state securities laws. in addition:

         (i)   the authorized capital of the Company consists of (A) 20,000,000
     shares of Common Stock, par value $0.0001 per share (the "Common Stock") of
     which, 6,428,880 shares are currently issued and outstanding, and (B)
     15,000,000 shares of Preferred Stock, par value $0.0001 per share (the
     "Preferred Stock"), 3,571,600 shares of which have been designated Series A
     Convertible Preferred Stock (the "Series A Preferred"), all of which are
     currently issued and outstanding and 7,346,108 shares of which have been
     designated Series B Convertible Preferred Stock (the "Series B Preferred"),
     all of which are currently issued and outstanding.  The Series A Preferred
     and the Series B Preferred are convertible, at the option of the holders
     thereof, into Common Stock at a current conversion ratio of 1:1.

          (ii) The Company has reserved 2,929,434 shares of Common Stock for
     issuance under its 1998 Stock Option Plan. In addition, the Company has
     reserved 25,000 shares of Common Stock for issuance under an option
     agreement with Jacob Avital. Other than as described in this subsection
     (d), there are no options, warrants, conversion privileges or other rights
     presently outstanding to

                                      -5-
<PAGE>

          purchase or otherwise acquire any authorized but unissued shares of
          the Company's capital stock or other securities of the Company.

          (iii)  In accordance with the terms of the Stockholders' Rights
     Agreement dated as of June 22, 1998 between the Company and the
     stockholders of the Company named therein, the holders of the Series B
     Preferred shall, subject to certain limited exceptions, have preemptive
     rights to purchase their pro rata share of any new issuances of the
     Company's capital stock.

     (e) Insurance. The Company has in full force and effect insurance policies,
         ---------
with extended coverage, insuring the Company and its property and business
against such losses and risks, and in such amounts, as are customary for
corporations engaged in a similar business and similarly situated and as
otherwise may be required pursuant to the terms of any other contract or
agreement.

     (f) Other Commitments to Register Securities.  Except as set forth in this
         ----------------------------------------
Warrant Agreement, the Company is not, pursuant to the terms of any other
agreement currently in existence, under any obligation to register under the
1933 Act any of its presently outstanding securities or any of its securities
which may hereafter be issued.

     (g) Exempt Transaction.  Subject to the accuracy of the Warrantholder's
         ------------------
representations in Section 10 hereof, the issuance of the Preferred Stock upon
exercise of this Warrant will constitute a transaction exempt from (i) the
registration requirements of Section 5 of the 1933 Act, in reliance upon Section
4(2) thereof, and (ii) the qualification requirements of the applicable state
securities laws.

     (h) Compliance with Rule 144.  At the written request of the Warrantholder,
         ------------------------
who proposes to sell Preferred Stock issuable upon the exercise of the Warrant
in compliance with Rule 144 promulgated by the Securities and Exchange
Commission, the Company shall furnish to the Warrantholder, within ten days
after receipt of such request, a written statement confirming the Company's
compliance with the filing requirements of the Securities and Exchange
Commission as set forth in such Rule, as such Rule may be amended from time to
time.

10.  REPRESENTATIONS AND COVENANTS OF THE WARRANTHOLDER.
     ---------------------------------------------------

     This Warrant Agreement has been entered into by the Company in reliance
upon the following representations and covenants of the Warrantholder:

     (a) Investment Purpose. The right to acquire Preferred Stock or the
         ------------------
Preferred Stock issuable upon exercise of the Warrantholder's rights contained
herein will be acquired for investment and not with a view to the sale or
distribution of any part thereof, and the Warrantholder has no present intention
of selling or engaging in any public distribution of the same except pursuant to
a registration or exemption.

     (b) Private Issue. The Warrantholder understands (i) that the Preferred
         -------------
Stock issuable upon exercise of this Warrant is not registered under the 1933
Act or qualified under applicable state securities laws on the ground that the
issuance contemplated by this Warrant Agreement will be exempt from the
registration and qualifications requirements thereof, and (ii) that the
Company's reliance on such exemption is prediated on the representations set
forth in this Section 10.

     (c) Disposition of Warrantholder's Rights. In no event will the
         -------------------------------------
Warrantholder make a disposition of any of its rights to acquire Preferred Stock
or Preferred Stock issuable upon exercise of such rights unless and until (i) it
shall have notified the Company of the proposed disposition, and (ii) if
requested by the Company, it shall have furnished the Company with an opinion of
counsel (which counsel may either be inside or outside counsel to the
Warrantholder) satisfactory to the Company and its counsel to the effect that
(A) appropriate action necessary for compliance with the 1933 Act has been
taken, or (B) an exemption from the registration requirements of the 1933 Act is
available. Notwithstanding the foregoing, the restrictions imposed upon the
transferability of any of its rights to acquire Preferred Stock or Preferred
Stock issuable on the exercise of such rights do not apply to transfers from the
beneficial owner of any of the aforementioned securities to its nominee or from
such nominee to its beneficial owner, and shall terminate as to any particular
share of Preferred Stock when (1) such security shall have been effectively
registered under the 1933 Act and sold by the holder thereof in accordance with
such registration or (2) such security shall have been sold without registration
in compliance with Rule 144 under the 1933 Act, or (3) a letter shall have been
issued to the Warrantholder at its request by the staff of the Securities and
Exchange Commission or a ruling shall have been issued to the Warrantholder at
its request by such Commission stating that no action shall be recommended by
such staff or taken by such Commission, as the case may be, if such security is
transferred without registration under the 1933 Act in accordance with the
conditions set forth in such letter or ruling and such letter or ruling
specifies that no subsequent restrictions on transfer are required. Whenever the
restrictions imposed

                                      -6-
<PAGE>

hereunder shall terminate, as hereinabove provided, the Warrantholder or holder
of a share of Preferred Stock then outstanding as to which such restrictions
have terminated shall be entitled to receive from the Company, without expense
to such holder, one or more new certificates for the Warrant or for such shares
of Preferred Stock not bearing any restrictive legend.

     (d) Financial Risk.  The Warrantholder has such knowledge and experience in
         --------------
financial and business matters as to be capable of evaluating the merits and
risks of its investment, and has the ability to bear the economic risks of its
investment.

     (e) Risk of No Registration.  The Warrantholder understands that if the
         -----------------------
Company does not register with the Securities and Exchange Commission pursuant
to Section 12 of the 1934 Act (the "l 934 Act"), or file reports pursuant to
Section 15(d), of the 1934 Act, or if a registration statement covering the
securities under the 1933 Act is not in effect when it desires to sell (i) the
rights to purchase Preferred Stock pursuant to this Warrant Agreement, or (ii)
the Preferred Stock issuable upon exercise of the right to purchase, it may be
required to hold such securities for an indefinite period.  The Warrantholder
also understands that any sale of its rights of the Warrantholder to purchase
Preferred Stock or Preferred Stock which might be made by it in reliance upon
Rule 144 under the 1933 Act may be made only in accordance with the terms and
conditions of that Rule.

     (f) Accredited Investor. Warrantholder is an "accredited investor" within
         -------------------
the meaning of the Securities and Exchange Rule 501 of Regulation D, as
presently in effect.

11.  TRANSFERS.
     ----------

     Subject to the terms and conditions contained in Section 10 hereof, this
Warrant Agreement and all rights hereunder are transferable in whole or in part
by the Warrantholder and any successor transferee, provided, however, in no
event shall the number of transfers of the rights and interests in all of the
Warrants exceed three (3) transfers.  The transfer shall be recorded on the
books of the Company upon receipt by the Company of a notice of transfer in the
form attached hereto as Exhibit III (the "Transfer Notice"), at its principal
offices and the payment to the Company of all transfer taxes and other
governmental charges imposed on such transfer.

12.  MISCELLANEOUS.
     --------------

     (a) Effective Date.  The provisions of this Warrant Agreement shall be
         --------------
construed and shall be given effect in all respects as if it had been executed
and delivered by the Company on the date hereof.  This Warrant Agreement shall
be binding upon any successors or assigns of the Company.

     (b) Attorney's Fees.  In any litigation, arbitration or court proceeding
         ---------------
between the Company and the Warrantholder relating hereto, the prevailing party
shall be entitled to attorneys' fees and expenses and all costs of proceedings
incurred in enforcing this Warrant Agreement.

     (c) Governing Law. This Warrant Agreement shall be governed by and
         -------------
construed for all purposes under and in accordance with the laws of the State of
Illinois.

     (d) Counterparts.  This Warrant Agreement may be executed in two or more
         ------------
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

     (e) Notices.  Any notice required or permitted hereunder shall be given in
         -------
writing and shall be deemed effectively given upon personal delivery, facsimile
transmission (provided that the original is sent by personal delivery or mail as
hereinafter set forth) or seven (7) days after deposit in the United States
mail, by registered or certified mail, addressed (i) to the Warrantholder at
6111 North River Road, Rosemont, Illinois 60018, Attention:  Venture Lease
Administration, cc: Legal Department, Attention:  General Counsel, (and/or, if
by facsimile, (847) 5185465 and (847) 518-5088) and (ii) to the Company at 1816
Embarcadero Road, Palo Alto, CA 94303, Attention:  Chief Financial Officer
(and/or if by facsimile, (650) 565-8300 or at such other address as any such
party may subsequently designate by written notice to the other party.

     (f) Remedies. In the event of any default hereunder, the non-defaulting
         --------
party may proceed to protect and enforce its rights either by suit in equity
and/or by action at law, including but not limited to an action for damages as a
result of any such default, and/or an action for specific performance for any
default where Warrantholder will not have an adequate remedy at law and where
damages will not be readily ascertainable. The Company expressly agrees that it
shall not oppose an application by the Warrantholder or any other person
entitled

                                      -7-
<PAGE>

to the benefit of this Agreement requiring specific performance of any or all
provisions hereof or enjoining the Company from continuing to commit any such
breach of this Agreement.

     (g) No Impairment of Rights.  The Company will not, by amendment of its
         -----------------------
Charter or through any other means, avoid or seek to avoid the observance or
performance of any of the terms of this Warrant, but will at all times in good
faith assist in the carrying out of all such terms and in the taking of all such
actions as may be necessary or appropriate in order to protect the rights of the
Warrantholder against impairment.

     (h) Survival.  The representations, warranties, covenants and conditions of
         --------
the respective parties contained herein or made pursuant to this Warrant
Agreement shall survive the execution and delivery of this Warrant Agreement.

     (i) Severability.  In the event any one or more of the provisions of this
         ------------
Warrant Agreement shall for any reason be held invalid, illegal or
unenforceable, the remaining provisions of this Warrant Agreement shall be
unimpaired, and the invalid, illegal or unenforceable provision shall be
replaced by a mutually acceptable valid, legal and enforceable provision, which
comes closest to the intention of the parties underlying the invalid, illegal or
unenforceable provision.

     (j) Amendments. Any provision of this Warrant Agreement may be amended by a
         ----------
written instrument signed by the Company and by the Warrantholder.

     (k) Additional Documents.  The Company, upon execution of this Warrant
         --------------------
Agreement, shall provide the Warrantholder with certified resolutions with
respect to the representations, warranties and covenants set forth in
subparagraphs (a) through (d), (f) and (g) of Section 9 above. If the purchase
price for the Leases referenced in the preamble of this Warrant Agreement
exceeds $1,000,000, the Company will also provide Warrantholder with an opinion
from the Company's counsel with respect to those same representations,
warranties and covenants. The Company shall also supply such other documents as
the Warrantholder may from time to time reasonably request.

     IN WITNESS WHEREOF, the parties hereto have caused this Warrant Agreement
to be executed by its officers thereunto duly authorized as of the Effective
Date.

                              COMPANY:  TIOGA SYSTEMS, INC.

                              By   /s/ Mark Pincus
                                  -----------------------------------------

                              Title   CEO
                                    ---------------------------------------

                              WARRANTHOLDER:  COMDISCO, INC.


                              By   /s/ JAMES P. LABE
                                 ------------------------------------------

                              Title PRESIDENT, COMDISCO VENTURES DIVISION
                                    ---------------------------------------

                                      -8-
<PAGE>

                                   EXHIBIT I

                              NOTICE OF EXERCISE

To:  ____________________________________

1.   The undersigned Warrantholder hereby elects to purchase _______ shares of
     the Series ___ Preferred Stock of ____________, pursuant to the terms of
     the Warrant Agreement dated the ___ day of ____________, 20__ (the "Warrant
     Agreement") between ____________ and the Warrantholder, and tenders
     herewith payment of the purchase price for such shares in full, together
     with all applicable transfer taxes, if any.

2.   In exercising its rights to purchase the Series __ Preferred Stock of
     ____________, the undersigned hereby confirms and acknowledges the
     investment representations and warranties made in Section 10 of the Warrant
     Agreement.

3.   Please issue a certificate or certificates representing said shares of
     Series __ Preferred Stock in the name of the undersigned or in such other
     name as is specified below.




_________________________________
(Name)


_________________________________
(Address)


Warrantholder:  COMDISCO, INC.

By_______________________________

Title____________________________

Date_____________________________

                                      -9-
<PAGE>

                                  EXHIBIT II

                          ACKNOWLEDGMENT OF EXERCISE

     The undersigned ____________, hereby acknowledge receipt of the "Notice of
Exercise" from Comdisco, Inc., to purchase _____ shares of the Series __
Preferred Stock of ___________ pursuant to the terms of the Warrant Agreement,
and further acknowledges that ____ shares remain subject to purchase under the
terms of the Warrant Agreement.

                                   COMPANY:

                                   By_______________________________

                                   Title____________________________

                                   Date_____________________________

                                      -10-
<PAGE>

                                  EXHIBIT III

                                TRANSFER NOTICE

(To transfer or assign the foregoing Warrant Agreement execute this form and
supply required information.  Do not use this form to purchase shares.)

     FOR VALUE RECEIVED, the foregoing Warrant Agreement and all rights
evidenced thereby are hereby transferred and assigned to


________________________________________________________
(Please Print)

whose address is________________________________________

________________________________________________________

     Dated______________________________________________

     Holder's Signature_________________________________

     Holder's Address___________________________________

     ___________________________________________________

Signature Guaranteed:___________________________________

NOTE:  The signature to this Transfer Notice must correspond with the name as it
       appears on the face of the Warrant Agreement, without alteration or
       enlargement or any change whatever. Officers of corporations and those
       acting in a fiduciary or other representative capacity should file proper
       evidence of authority to assign the foregoing Warrant Agreement.

                                      -11-