<PAGE>   1
                                                                     EXHIBIT 4.1




                              ACCRUE SOFTWARE, INC.






                           INVESTORS' RIGHTS AGREEMENT





                                  JULY 14, 2000

<PAGE>   2

                                TABLE OF CONTENTS


<TABLE>
<CAPTION>
                                                                                          Page
                                                                                          ----
<S>     <C>                                                                               <C>
1.      Amendment...........................................................................1

        1.1    Procedure....................................................................1
        1.2    Rights of Holders............................................................1

2.      Registration Rights.................................................................1

        2.1    Definitions..................................................................1
        2.2    Form S-3 Registration........................................................2
        2.3    Obligations of the Company...................................................4
        2.4    Furnish Information..........................................................5
        2.5    No Delay of Registration.....................................................5
        2.6    Indemnification..............................................................5
        2.7    Reports Under Securities Exchange Act of 1934................................7
        2.8    Assignment of Registration Rights............................................8
        2.9    Termination of Registration Rights...........................................8
        2.10   Piggyback Registration Rights................................................8

3.      Miscellaneous.......................................................................8

        3.1    Assignment...................................................................8
        3.2    Third Parties................................................................8
        3.3    Governing Law................................................................9
        3.4    Counterparts.................................................................9
        3.5    Notices......................................................................9
        3.6    Severability.................................................................9
        3.7    Delays or Omissions..........................................................9
</TABLE>

<PAGE>   3

                           INVESTORS' RIGHTS AGREEMENT


        THIS INVESTORS' RIGHTS AGREEMENT (the "Agreement") is entered into as of
July 14, 2000, by and between Accrue Software, Inc., a Delaware corporation (the
"Company") and Tantau Software, Inc., a Delaware corporation (the "Investor").

                                    RECITALS

        A. The Company, Investor and Tantau Software International, Inc., a
Delaware corporation and a wholly owned subsidiary of Investor ("Investor Sub")
have entered into an Asset Purchase Agreement of even date herewith (the
"Purchase Agreement") pursuant to which Investor and Investor Sub are selling to
the Company certain of the assets relating to Investor's Infocharger division
and as partial consideration therefor the Company is issuing and selling to
Investor shares of its Common Stock, $0.001 par value per share.

        B. A condition to Investor's and Investor Sub's obligation to effect the
closing of the transactions contemplated by the Purchase Agreement is that the
Company grant Investor the registration rights set forth herein.

        C. The Company wishes to execute this Agreement and grant to Investor
the rights contained herein in order to fulfill such condition.

        THE PARTIES AGREE AS FOLLOWS:

        1.     Amendment.

               1.1 Procedure. Except as expressly provided herein, neither this
Agreement nor any term hereof may be amended, waived, discharged or terminated
other than by a written instrument signed by the party against whom enforcement
of any such amendment, waiver, discharge or termination is sought.

               1.2 Rights of Holders. Each holder of Registrable Securities
(as defined in Section 2.1 herein below) shall have the absolute right to
exercise or refrain from exercising any right or rights that such holder may
have by reason of this Agreement, including, without limitation, the right to
consent to the waiver or modification of any obligation under this Agreement,
and such holder shall not incur any liability to any other holder of any
securities of the Company as a result of exercising or refraining from
exercising any such right or rights.

        2.     Registration Rights.

               2.1 Definitions.  As used in this Agreement:

                      (a) The terms "register," "registered," and "registration"
refer to a registration effected by preparing and filing a registration
statement in compliance with the Securities Act of 1933, as amended (the
"Securities Act"), and the subsequent declaration or ordering of the
effectiveness of such registration statement.

<PAGE>   4

                      (b) The term "Registrable Securities" means:

                            (i) The shares of Common Stock (the "Stock") issued
to Investor by the Company upon the Closing of the Purchase Agreement, including
the Stock delivered to the Depository Agent, as such term is defined in the
Purchase Agreement; and

                            (ii) Any other shares of Common Stock of the Company
issued as (or issuable upon the conversion or exercise of any warrant, right or
other security which is issued as) a dividend or other distribution with respect
to, or in exchange for or in replacement of, the Stock, excluding in all cases,
however, any Registrable Securities sold by a person in a transaction in which
his or her rights under this Agreement are not assigned; provided, however, that
Common Stock or other securities shall only be treated as Registrable Securities
if and so long as they have not been (A) sold to or through a broker or dealer
or underwriter in a public distribution or a public securities transaction, or
(B) sold in a transaction exempt from the registration and prospectus delivery
requirements of the Securities Act under Section 4(1) thereof so that all
transfer restrictions, and restrictive legends with respect thereto, if any, are
removed upon the consummation of such sale.

                      (c) The number of shares of "Registrable Securities then
outstanding" shall be determined by the number of shares of Common Stock or
other securities outstanding which are, and the number of shares of Common Stock
or other securities issuable pursuant to then exercisable or convertible
securities which are, Registrable Securities.

                      (d) The term "Holder" means any holder of outstanding
Registrable Securities who, subject to the limitations set forth in Section 2.8
below, acquired such Registrable Securities in a transaction or series of
transactions not involving any registered public offering.

                      (e) The term "Form S-3" means such form under the
Securities Act as in effect on the date hereof or any registration form under
the Securities Act subsequently adopted by the Securities and Exchange
Commission ("SEC") which permits inclusion or incorporation of substantial
information by reference to other documents filed by the Company with the SEC.

               2.2 Form S-3 Registration. In case the Company shall receive at
any time after August 1, 2000 from the Holder or Holders (the "S-3 Initiating
Holders") of the Registrable Securities a written request or requests that the
Company effect a registration on Form S-3 and any related qualification or
compliance with respect to all or a part of the Registrable Securities owned by
such Holder or Holders, the Company will:

                      (a) promptly give written notice of the proposed
registration, and any related qualification or compliance, to all other Holders;
and

                      (b) as soon as practicable, effect such registration and
all such qualifications and compliances as may be so requested and as would
permit or facilitate the sale



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<PAGE>   5

and distribution of all or such portion of such Holder's or Holders' Registrable
Securities as are specified in such request, together with all or such portion
of the Registrable Securities of any other Holder or Holders joining in such
request as are specified in a written request given within 15 days after receipt
of such written notice from the Company; provided, however, that the Company
shall not be obligated to effect any such registration, qualification or
compliance, pursuant to this Section 2.2, (1) if Form S-3 is not available for
such offering by the Holders; (2) if the Holders, together with the holders of
any other securities of the Company entitled to inclusion in such registration,
propose to sell Registrable Securities and such other securities (if any) at an
aggregate price to the public (net of any underwriters' discounts or
commissions) of less than $500,000; (3) if the Company shall furnish to the
Holders a certificate signed by the president of the Company stating that in the
good faith judgment of the Board of Directors of the Company, it would be
detrimental to the Company and its stockholders for such Form S-3 Registration
to be effected at such time, in which event the Company shall have the right to
defer the filing of the Form S-3 registration statement for a period of not more
than ninety (90) days after receipt of the request of the Holder or Holders
under this Section 2.2; provided, however, that the Company shall not utilize
this right more than once in any twelve month period; or (4) in any particular
jurisdiction in which the Company would be required to qualify to do business or
to execute a general consent to service of process in effecting such
registration, qualification or compliance. Notwithstanding any other provision
of this Section 2.2, if the Company or an underwriter advising the Company
advises the S-3 Initiating Holders in writing that marketing factors require a
limitation of the number of shares to be included in any registration on Form
S-3, then the S-3 Initiating Holders shall so advise all Holders of Registrable
Securities which would otherwise be included in such registration on Form S-3
hereunder, and the number of shares of Registrable Securities that may be
included in the registration shall be allocated among all Holders thereof,
including the S-3 Initiating Holders, in proportion (as nearly as practicable)
to the amount of Registrable Securities of the Company owned by each Holder.

                (c) Subject to the foregoing, the Company shall file a
registration statement covering the Registrable Securities and other securities
so requested to be registered as soon as practicable after receipt of the
request or requests of the Holders. All expenses other than stock transfer
taxes, the fees and disbursements of special counsel for individual Holders,
underwriting discounts and commissions incurred in connection with a
registration requested pursuant to Section 2.2, including (without limitation)
all registration, filing, qualification, printer's and accounting fees and the
reasonable fees and disbursements of counsel for the selling Holder or Holders
(not to exceed $15,000) and counsel for the Company, shall be borne by the
Company; provided, however, that the Company shall not be required to pay for
any expenses of any registration proceeding begun pursuant to this Section 2.2
if the registration request is subsequently withdrawn at the request of the
Holders of a majority of the Registrable Securities to be registered (in which
case all Participating Holders shall bear such expenses); provided further,
however, that if at the time of such withdrawal, the Holders have learned of a
material adverse change in the condition, business, or prospects of the Company
from that known to the Holders at the time of their request, then the Holders
shall not be required to pay any of such expenses and shall retain their rights
pursuant to this Section 2.2.



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                      (d) The Company is obligated to effect only one (1) such
registration on Form S-3 pursuant to this Section 2.2.

               2.3 Obligations of the Company. Whenever required under this
Section 2 to effect the registration of any Registrable Securities, the Company
shall, as expeditiously as reasonably possible:

                      (a) Prepare and file with the SEC a registration statement
with respect to such Registrable Securities and use its best efforts to cause
such registration statement to become effective, and keep such registration
statement effective until the distribution contemplated in the Registration
Statement has been completed; provided that Rule 415, or any successor rule
under the Act, permits an offering on a continuous or delayed basis, and
provided further that applicable rules under the Act governing the obligation to
file a post-effective amendment permit, in lieu of filing a post-effective
amendment which (I) includes any prospectus required by Section 10(a)(3) of the
Act or (II) reflects facts or events representing a material or fundamental
change in the information set forth in the registration statement, the
incorporation by reference of information required to be included in (I) and
(II) above to be contained in periodic reports filed pursuant to Section 13 or
15(d) of the Securities Exchange Act of 1934, as amended, (the "1934 Act") in
the registration statement.

                      (b) Prepare and file with the SEC such amendments and
supplements to such registration statement and the prospectus used in connection
with such registration statement as may be necessary to comply with the
provisions of the Securities Act with respect to the disposition of all
securities covered by such registration statement.

                      (c) Furnish to the Holders such reasonable numbers of
copies of a prospectus, including a preliminary prospectus, in conformity with
the requirements of the Securities Act, and such other documents as they may
reasonably request in order to facilitate the disposition of Registrable
Securities owned by them.

                      (d) Use its best efforts to register and qualify the
securities covered by such registration statement under such other securities or
Blue Sky laws of such jurisdictions as shall be reasonably requested by the
Holders, provided that the Company shall not be required in connection therewith
or as a condition thereto to qualify to do business or to file a general consent
to service of process in any such states or jurisdictions.

                      (f) Notify each Holder of Registrable Securities covered
by such registration statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act of the happening of any event
as a result of which the prospectus included in such registration statement, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading in the light of the circumstances then
existing.

                      (g) Furnish, at the request of any Holder requesting
registration of Registrable Securities pursuant to this Section 2, on the date
that the registration statement with respect to such securities becomes
effective, (i) an opinion, dated such date, of the counsel



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<PAGE>   7

representing the Company for the purposes of such registration, in form and
substance as is customarily given to underwriters in an underwritten public
offering, addressed to the underwriters, if any, and to the Holders requesting
registration of Registrable Securities and (ii) a letter dated such date, from
the independent public accountants of the Company, in form and substance as is
customarily given by independent certified public accountants to underwriters in
an underwritten public offering, addressed to the underwriters, if any, and to
the Holders requesting registration of Registrable Securities.

                      (h) Cause all such Registrable Securities registered
pursuant hereunder to be listed on each securities exchange or automated
quotation system on which similar securities issued by the Company are then
listed.

               2.4 Furnish Information. It shall be a condition precedent to the
obligations of the Company to take any action pursuant to this Section 2 with
respect to the Registrable Securities of any selling Holder that such Holder
shall furnish to the Company such information regarding itself, the Registrable
Securities held by it, and the intended method of disposition of such securities
as shall be required to effect the registration of such Holder's Registrable
Securities.

               2.5 No Delay of Registration. No Holder shall have any right to
obtain or seek an injunction restraining or otherwise delaying any such
registration as the result of any controversy that might arise with respect to
the interpretation or implementation of this Section 2.

               2.6 Indemnification. In the event any Registrable Securities are
included in a registration statement under this Section 2:

                      (a) To the extent permitted by law, the Company will
indemnify and hold harmless each Holder, and each person, if any, who controls
such Holder within the meaning of the Securities Act or the 1934 Act, against
any losses, claims, damages, or liabilities (joint or several) to which they may
become subject under the Securities Act, the 1934 Act or other federal or state
law, insofar as such losses, claims, damages, or liabilities (or actions in
respect thereof) arise out of or are based upon any of the following statements,
omissions or violations (collectively a "Violation"): (i) any untrue statement
or alleged untrue statement of a material fact contained in such registration
statement, including any preliminary prospectus or final prospectus contained
therein or any amendments or supplements thereto, (ii) the omission or alleged
omission to state therein a material fact required to be stated therein, or
necessary to make the statements therein not misleading, or (iii) any violation
or alleged violation by the Company of the Securities Act, the 1934 Act, any
state securities law or any rule or regulation promulgated under the Securities
Act, the 1934 Act or any state securities law; and the Company will pay, as
incurred, to each such Holder, underwriter or controlling person, any legal or
other expenses reasonably incurred by them in connection with defending any such
loss, claim, damage, liability, or action; provided, however, that the indemnity
agreement contained in this subsection 2.6(a) shall not apply to amounts paid in
settlement of any such loss, claim, damage, liability, or action if such
settlement is effected without the consent of the Company (such



                                      -5-
<PAGE>   8

consent not to be unreasonably withheld), nor shall the Company be liable in any
such case for any such loss, claim, damage, liability, or action to the extent
that it arises out of or is based upon a Violation which occurs in reliance upon
and in conformity with written information furnished expressly for use in
connection with such registration by any such Holder, underwriter or controlling
person.

                      (b) To the extent permitted by law, each selling Holder
will indemnify and hold harmless the Company, each of its directors, each of its
officers who has signed the registration statement, each person, if any, who
controls the Company within the meaning of the Securities Act, any underwriter,
any other Holder selling securities in such registration statement and any
controlling person of any such underwriter or other Holder, against any losses,
claims, damages, or liabilities (joint or several) to which any of the foregoing
persons may become subject, under the Securities Act, the 1934 Act or other
federal or state law, insofar as such losses, claims, damages, or liabilities
(or actions in respect thereto) arise out of or are based upon any Violation, in
each case to the extent (and only to the extent) that such Violation occurs in
reliance upon and in conformity with written information furnished by such
Holder expressly for use in connection with such registration; and each such
Holder will pay, as incurred, any legal or other expenses reasonably incurred by
any person intended to be indemnified pursuant to this subsection 2.6(b), in
connection with defending any such loss, claim, damage, liability, or action;
provided, however, that the indemnity agreement contained in this subsection
2.6(b) shall not apply to amounts paid in settlement of any such loss, claim,
damage, liability or action if such settlement is effected without the consent
of the Holder (such consent not to be unreasonably withheld); provided further,
that in no event shall any indemnity under this Section 2.6(b) exceed the net
proceeds from the offering received by such Holder, except in the case of
willful fraud by such Holder.

                      (c) Promptly after receipt by an indemnified party under
this Section 2.6 of notice of the commencement of any action (including any
governmental action), such indemnified party will, if a claim in respect thereof
is to be made against any indemnifying party under this Section 2.6, deliver to
the indemnifying party a written notice of the commencement thereof and the
indemnifying party shall have the right to participate in, and, to the extent
the indemnifying party so desires, jointly with any other indemnifying party
similarly noticed, to assume the defense thereof with counsel mutually
satisfactory to the parties; provided, however, that an indemnified party shall
have the right to retain its own counsel, with the fees and expenses to be paid
by the indemnifying party, if representation of such indemnified party by the
counsel retained by the indemnifying party would be inappropriate due to actual
or potential differing interests between such indemnified party and any other
party represented by such counsel in such proceeding. The failure to deliver
written notice to the indemnifying party within a reasonable time of the
commencement of any such action, if prejudicial to its ability to defend such
action, shall relieve such indemnifying party of any liability to the
indemnified party under this Section 2.6 (to the extent of such prejudicial
effect), but the omission so to deliver written notice to the indemnifying party
will not relieve it of any liability that it may have to any indemnified party
otherwise than under this Section 2.6.



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<PAGE>   9

                      (d) No indemnifying party, in the defense of any claim
arising out of a Violation shall, except with the consent of each indemnified
party, consent to entry of any judgment or enter into any settlement which does
not include as an unconditional term thereof the giving by the claimant or
plaintiff to such indemnified party of a release from all liability in respect
to such claim or litigation and, in the event the terms of such judgment or
settlement include any term other than the payment by the indemnifying party of
money damages, the indemnifying party shall not so consent or enter into such a
settlement without the consent of each indemnified party (which will not be
unreasonably withheld) whether or not the terms thereof include such a release.

                      (e) The obligations of the Company and Holders under this
Section 2.6 shall survive the completion of any offering of Registrable
Securities in a registration statement under this Section 2, and otherwise.

                      (f) Notwithstanding the foregoing, to the extent that the
provisions on indemnification and contribution contained in the underwriting
agreement entered into in connection with the underwritten public offering are
in conflict with the foregoing provisions, the provisions in the underwriting
agreement shall control.

               2.7 Reports Under Securities Exchange Act of 1934. With a view to
making available to the Holders the benefits of Rule 144 promulgated under the
Securities Act and any other rule or regulation of the SEC that may at any time
permit a Holder to sell securities of the Company to the public without
registration or pursuant to a registration on Form S-3, the Company agrees to:

                      (a) Make and keep public information available, as those
terms are understood and defined in SEC Rule 144, at all times after ninety (90)
days after the effective date of the first registration statement filed by the
Company for the offering of its securities to the public;

                      (b) take such action, including the voluntary registration
of its Common Stock under Section 12 of the 1934 Act, as is necessary to enable
the Holders to utilize Form S-3 for the sale of their Registrable Securities,
such action to be taken as soon as practicable after the end of the fiscal year
in which the first registration statement filed by the Company for the offering
of its securities to the general public is declared effective;

                      (c) File with the SEC in a timely manner all reports and
other documents required of the Company under the Securities Act and the 1934
Act; and

                      (d) Furnish to any Holder, so long as the Holder owns any
Registrable Securities, forthwith upon request (i) a written statement by the
Company that it has complied with the reporting requirements of SEC Rule 144 (at
any time after ninety (90) days after the effective date of the first
registration statement filed by the Company), the Securities Act and the 1934
Act (at any time after it has become subject to such reporting requirements), or
that it qualifies as a registrant whose securities may be resold pursuant to
Form S-3 (at any time after it so qualifies), (ii) a copy of the most recent
annual or quarterly report of the Company and such other reports and documents
so filed by the Company, and (iii) such other information as may be



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<PAGE>   10

reasonably requested in availing any Holder of any rule or regulation of the SEC
which permits the selling of any such securities without registration.

               2.8 Assignment of Registration Rights. The rights to cause the
Company to register Registrable Securities pursuant to this Section 2 may only
be assigned by a Holder to a transferee who acquires at least 250,000 shares of
Registrable Securities (subject to appropriate adjustment for any stock split,
reverse stock split, stock dividend, recapitalization or similar transaction),
provided the Company is, prior to such transfer, furnished with written notice
of the name and address of such transferee; and provided, further, that such
assignment shall be effective only if immediately following such transfer the
further disposition of such securities by the transferee or assignee is
restricted under the Securities Act.

               2.9 Termination of Registration Rights. No Holder shall be
entitled to exercise any right provided for in this Agreement after the three
year anniversary of the date of this Agreement or at such time as such Holder is
may dispose of all of its Registrable Securities under Rule 144 under the
Securities Act in any three-month period.

               2.10 Piggyback Registration Rights. If subsequent to the date of
this Agreement and prior to August 1, 2000, the Company grants to any third
party (a "New Holder") the right to cause to be registered under the Securities
Act all of the Registrable Securities that such New Holder has requested to be
registered ("Piggyback Registration Rights") in connection with the public
offering by the Company prior to August 1, 2000 of its securities solely for
cash (other than a registration relating either to the sale of securities to
participants in a Company stock option, stock purchase or similar plan or to an
SEC Rule 145 transaction, or a registration on any form which does not include
substantially similar information as would be required to be included in a
registration statement covering the sale of the Registrable Securities), then
the Company shall grant to Investor comparable Piggyback Registration Rights.

        3.     Miscellaneous.

               3.1 Assignment. Subject to the provisions of Section 2.8 hereof,
the terms and conditions of this Agreement shall inure to the benefit of and be
binding upon the respective successors and assigns of the parties hereto.

               3.2 Third Parties. Nothing in this Agreement, express or implied,
is intended to confer upon any party, other than the parties hereto, and their
respective successors and assigns, any rights, remedies, obligations or
liabilities under this Agreement, except as expressly provided herein.

               3.3 Governing Law. This Agreement shall be governed by and
construed under the laws of the State of California as applied to agreements
among California residents entered into and to be performed entirely within
California.

               3.4 Counterparts. This 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.



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<PAGE>   11

               3.5 Notices.

                      (a) All notices, requests, demands and other
communications under this Agreement or in connection herewith shall be given to
or made upon the respective parties at the addresses set forth on the signature
page hereto.

                      (b) All notices, requests, demands and other
communications given or made in accordance with the provisions of this Agreement
shall be in writing, and shall be sent by airmail, return receipt requested, or
by telex or telecopy (facsimile) with confirmation of receipt, and shall be
deemed to be given or made when receipt is so confirmed.

                      (c) Any party may, by written notice (in accordance with
this Section 3.5) to the other, alter its address or respondent.

               3.6 Severability. If one or more provisions of this Agreement are
held to be unenforceable under applicable law, portions of such provisions, or
such provisions in their entirety, to the extent necessary, shall be severed
from this Agreement, and the balance of this Agreement shall be enforceable in
accordance with its terms.

               3.7 Delays or Omissions. No delay or omission to exercise any
right, power or remedy accruing to any party to this Agreement, upon any breach
or default of the other party, shall impair any such right, power or remedy of
such non-breaching party nor shall it be construed to be a waiver of any such
breach or default, or an acquiescence therein, or of or in any similar breach or
default thereafter occurring; nor shall any waiver of any single breach or
default be deemed a waiver of any other breach or default theretofore or
thereafter occurring. Any waiver, permit, consent or approval of any kind or
character on the part of any party of any breach or default under this
Agreement, or any waiver on the part of any party of any provisions or
conditions of this Agreement, must be made in writing and shall be effective
only to the extent specifically set forth in such writing. All remedies, either
under this Agreement, or by law or otherwise afforded to any Holder, shall be
cumulative and not alternative.



                            [SIGNATURE PAGES FOLLOW]



                                      -9-
<PAGE>   12

               IN WITNESS WHEREOF, the parties have executed this Investors'
Rights Agreement as of the date first written above.

                                        COMPANY:

                                        ACCRUE SOFTWARE, INC.,
                                        a Delaware corporation


                                        By:
                                            ------------------------------------

                                        Title:
                                              ----------------------------------

                                        Address:
                                                --------------------------------

                                                --------------------------------


                                        Fax No.:
                                                --------------------------------

                                        Dated:
                                              ----------------------------------



                                        INVESTOR:

                                        TANTAU SOFTWARE, INC.,
                                        a Delaware corporation


                                        Name:
                                             -----------------------------------


                                        By:
                                           -------------------------------------

                                        Title:
                                              ----------------------------------

                                        Address:
                                                --------------------------------

                                                --------------------------------


                                        Fax No.:
                                                --------------------------------

                                        Dated:
                                              ----------------------------------