Document:

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                                 Exhibit 10 (a)

                           REPLACEMENT REVOLVING NOTE

$35,000,000                                           Dated as of June 30, 2002
                                                            Due:  June 30, 2003

         On or before June 30, 2003, CDW COMPUTER CENTERS, INC. (the
"Undersigned"), for value received, promises to pay to the order of LASALLE BANK
NATIONAL ASSOCIATION, a national banking association (hereinafter, together with
any holder thereof, called "Bank"), whose address is 135 S. LaSalle Street,
Chicago, Illinois 60603, the principal sum of Thirty Five Million Dollars
($35,000,000) or if less, the aggregate unpaid principal amount of all loans
made by the Bank to the Undersigned hereunder (this "Note"). The unpaid
principal amount hereof shall bear interest at the Undersigned's option of the
following:

                  (i)  a fixed rate equal to the greater of (A) the "Prime Rate"
         (hereinafter defined) minus two and one-half percent (-2 1/2%) per
         annum, or (B) the "Federal Funds Rate" (hereinafter defined) plus
         one-half of one percent (+1/2%) per annum, for borrowings not to exceed
         thirty (30) days, such rate to be fixed at the beginning of the term of
         such borrowing (the "Fixed Prime Rate"); or

                  (ii)  a floating rate equal to the greater of (A) the Prime
         Rate minus two and one-half percent (-2 1/2%) per annum, or (B) the
         Federal Funds Rate plus one-half of one percent (+1/2%) per annum, for
         borrowings in excess of thirty (30) days (the "Floating Prime Rate");
         the Floating Prime Rate and the Fixed Prime Rate are referred to herein
         collectively as the "Prime Rate"); or

                  (iii) "Adjusted LIBOR" (hereinafter defined).

         1.    For purposes hereof the following terms shall have the following
         definitions:

                  "Prime Rate" shall mean the rate in effect from time to time
         as set by the Bank and called its Prime Rate. The effective date of any
         change in said Prime Rate shall for purposes hereof be the date the
         rate is changed by the Bank. The Bank shall not be obligated to give
         notice of any change in the Prime Rate.

                  "Federal Funds Rate" shall mean, for any day, the daily
         effective Federal Funds rate for such day as published in the Federal
         Reserve Statistical Release H.15("H.15") (or, if such Release is not
         published, the successor thereto or closest approximation thereto, as
         determined by the Bank) for such day; provided that, the Federal Funds
         Rate for any day on which the Federal Reserve Bank of New York, (the
         "New York Fed") is not open for business shall be the Federal Funds
         Rate for the next preceding day on which the New York Fed was open for
         business; and provided, further, that if the Bank determines, in good
         faith, that it is unable to determine the Federal Funds Rate on the
         basis of H.15, then the Bank shall determine the Federal Funds Rate
         based on the quotations of three (3) dealers in Federal Funds in New
         York City, as reasonably selected by the Bank, and the Bank's
         determination of such rate shall be binding and conclusive absent
         manifest error.

                  "Adjusted LIBOR" means a rate of interest equal to one-half of
         one percent (1/2%) per annum in excess of the per annum rate of
         interest at which U.S. dollar deposits in an amount comparable to the
         amount of the relevant "LIBOR Loan" (hereinafter defined) and for a
         period equal to the relevant "Interest Period" (hereinafter defined)
         are offered generally to the Bank (rounded upward, if necessary, to the
         nearest 1/16 of 1.00%) in the London Interbank Eurodollar market at
         11:00 a.m. (London time) two (2) banking days prior to the commencement
         of each Interest Period, such rate to remain fixed for such Interest
         Period.

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                  "Interest Period" shall mean successive one, two or
         three-month periods as selected from time to time by the Undersigned by
         notice given to the Bank not less than three (3) business days prior to
         the first day of each respective Interest Period; provided that: (i)
         each such one, two or three-month period occurring after such initial
         period shall commence on the day on which the next preceding period
         expires; (ii) the final Interest Period shall be such that its
         expiration occurs on or before the stated maturity date of the Note;
         and (iii) if for any reason the Undersigned shall fail to select timely
         a period, then it shall be deemed to have selected a LIBOR Loan with a
         one(1) month Interest Period; provided that, at any time any Interest
         Period expires less than one (1) month before the maturity of the Note,
         then, for the period commencing on such expiration date and ending on
         the maturity date such LIBOR Loan shall convert to a loan bearing
         interest at the Floating Prime Rate.

         2. Interest on that portion of the outstanding principal amount hereof
bearing interest at the Prime Rate shall be payable from the date hereof on such
aggregate unpaid principal amount on the last day of each month, commencing on
July 31, 2002, and at maturity hereof. Interest on LIBOR borrowings shall be
payable at the end of each respective Interest Period. Interest after maturity
(whether by reason of acceleration or otherwise) shall be paid on the unpaid
balance at the rate of the Floating Prime Rate plus two percent (2%) per annum
(the "Default Rate"). Interest shall be computed on the basis of a year
consisting of 360 days and shall be paid for the actual number of days elapsed,
unless otherwise specified herein.

         3. Each LIBOR borrowing hereunder (each, a "LIBOR Loan") must equal
$100,000 or an integral multiple thereof. Interest on each LIBOR Loan shall be
payable on the last banking day of each Interest Period with respect thereto,
commencing on the first such date to occur after the date hereof, at maturity,
after maturity on demand, and on the date of any payment hereon on the amount
paid. The Undersigned hereby further promises to pay to the order of the Bank,
on demand, interest on the unpaid principal amount hereof after maturity
(whether by acceleration or otherwise) at the Default Rate.

         4. Provisions applicable to LIBOR Loans: (a) The Bank's determination
of Adjusted LIBOR as provided above shall be conclusive, absent manifest error.
Furthermore, if the Bank determines, in good faith (which determination shall be
conclusive, absent manifest error), prior to the commencement of any Interest
Period that (a) U.S. dollar deposits of sufficient amount and maturity for
funding any LIBOR Loan are not available to the Bank in the London Interbank
Eurodollar market in the ordinary course of business, or (b) by reason of
circumstances affecting the London Interbank Eurodollar market, adequate and
fair means do not exist for ascertaining the rate of interest to be applicable
to the relevant LIBOR Loan, the Bank shall promptly notify the Undersigned and
such LIBOR Loan shall automatically convert on the last day of its then-current
Interest Period to a loan bearing interest at the Floating Prime Rate.

         If, after the date hereof, the introduction of, or any change in any
applicable law, treaty, rule, regulation or guideline or in the interpretation
or administration thereof by any governmental authority or any central bank or
other fiscal, monetary or other authority having jurisdiction over the Bank or
its lending office (a "Regulatory Change"), shall, in the opinion of counsel to
the Bank, makes it unlawful for the Bank to make or maintain any LIBOR Loan
evidenced hereby, then the Bank shall promptly notify the Undersigned and such
LIBOR Loan shall automatically convert on the last day of its then-current
Interest Period to a loan bearing interest at the Floating Prime Rate.

         If, for any reason, any LIBOR Loan is paid prior to the last business
day of its then-current Interest Period, the Undersigned agrees to indemnify the
Bank against any loss (including any loss on redeployment of the funds repaid),
cost or expense incurred by the Bank as a result of such prepayment.

         If any Regulatory Change (whether or not having the force of law) shall
(a) impose, modify or deem applicable any assessment, reserve, special deposit
or similar requirement against assets held by, or deposits in or for the account
of or loans by, or any other acquisition of funds or disbursements by, the Bank;
(b) subject the Bank or any LIBOR Loan to any tax, duty, charge, stamp tax or
fee or change the basis of taxation of payments to the Bank of principal or
interest due from the Undersigned to the Bank hereunder (other than a change in
taxation of the overall net income of the Bank); or (c) impose on the Bank any
other condition regarding such LIBOR Loan or the Bank's funding thereof, and the
Bank shall determine (which determination shall be

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conclusive,  absent  manifest  error)  that the  result of the  foregoing  is to
increase  the cost to the Bank of making or  maintaining  such  LIBOR Loan or to
reduce the amount of principal or interest received by the Bank hereunder,  then
the  Undersigned   shall  pay  to  the  Bank,  on  demand  and  presentation  of
satisfactory  documentation therefor, such additional amounts as the Bank shall,
from time to time, determine are sufficient to compensate and indemnify the Bank
for such increased cost or reduced amount.

         5. The Undersigned hereby authorizes the Bank to charge any account of
the Undersigned for all sums due hereunder. Principal payments submitted in
funds not available until collected shall continue to bear interest until
collected. If payment hereunder becomes due and payable on a Saturday, Sunday or
legal holiday under the laws of the United States or the State of Illinois, the
due date thereof shall be extended to the next succeeding business day, and
interest shall be payable thereon at the rate specified during such extension.

         6. This Note evidences a revolving line of credit under which the
Undersigned is indebted to the Bank and evidences the aggregate unpaid principal
amount of all advances made or to be made by the Bank to the Undersigned under
the Note. All advances and repayments hereunder shall be evidenced by entries on
the books and records of the Bank which shall be presumptive evidence of the
principal amount and interest owing and unpaid on this Note, or any renewal or
extension hereof. The failure to so record any such amount or any error so
recording any such amount shall not, however, limit or otherwise affect the
obligations of the Undersigned hereunder or under any not to repay the principal
amount of the liabilities together with all interest accruing thereon. This Note
may be used for direct advances or letters of credit. Each letter of credit
requested by the Undersigned shall be subject to the terms and conditions of the
Bank's standard letter of credit application, which application is incorporated
herein by this reference. The amount available to the Undersigned under this
Note shall be reduced by the face amount of all letters of credit issued and
outstanding hereunder. All letters of credit issued hereunder shall have an
expiry date no later than June 30, 2004. The Undersigned and the Bank agree that
each draw under any letter of credit shall constitute, and shall be repaid by, a
direct advance under this Note on the date of such draw. Each letter of credit
requested by the Undersigned hereunder shall be issued by the Bank only after
the Bank has received a fully executed letter of credit application on the
Bank's standard form and the Bank's customary fees for issuance of letters of
credit.

         7. Advances under this Note may be made by the Bank upon the written
request of any two (2) authorized officers of the Undersigned whose authority to
so act has not been revoked by the Undersigned in writing theretofore received
by the Bank at its main office. Any such advances shall be conclusively presumed
to have been made by the Bank to or for the benefit of the Undersigned. The
Undersigned does hereby irrevocably confirm, ratify and approve all such
advances by the Bank and does hereby indemnify the Bank against loss and
reasonable expenses (including court costs, attorneys' and paralegals' fees) and
shall hold the Bank harmless with respect thereto.

         8. The Undersigned shall be in default hereunder if: (a) any amount
payable on this and any and all other liabilities or obligations of the
Undersigned to the Bank, howsoever created, arising or evidenced, whether now
existing or hereafter arising, whether now due or to become due, whether direct,
indirect, absolute, contingent, joint, several or joint and several (all such
liabilities and obligations, including this Note, are hereinafter referred to as
the "Obligations") or on the obligations of any obligor hereunder, it not paid
within five (5) days of when due; or (b) the Undersigned shall otherwise fail to
perform any of the promises to be performed by the Undersigned hereunder or
under any other security agreement or other agreement with the Bank and the same
is not cured within thirty (30) days of notice thereof by the Bank; or (c) the
Undersigned, or any other party liable with respect to the Obligations, or any
guarantor or accommodation endorser or third party pledgor, shall make any
assignment for the benefit of creditors, or there shall be commenced any
bankruptcy, receivership, insolvency, reorganization, dissolution or liquidation
proceedings by or against, or the entry of any judgment, levy, attachment,
garnishment or other process, or the filing of any lien against the Undersigned
or any guarantor, or any other party liable with respect to the Obligations, or
accommodation endorser or third party pledgor for any of the Obligations which
has a material adverse effect on such party; or (d) the determination by the
Bank that a material adverse change has occurred in the financial condition of
the Undersigned from the condition set forth in the most recent financial
statement of the Undersigned furnished to the Bank, or from the financial
condition of the Undersigned most recently disclosed to the Bank in any manner
and the same is not cured within thirty (30) days of notice thereof by the Bank;
or (e) any oral or written

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warranty, representation, certificate or statement of the Undersigned to the
Bank is untrue in any material respect; or (f) failure of the Undersigned,
within thirty (30) days after a request by the Bank, to furnish  financial
information or to permit inspection by the Bank of the Undersigned's books and
records; or (g) the occurrence of any material  adverse event which causes a
change in the financial condition of the Undersigned, or which would have a
material adverse effect on the business of the  Undersigned and the same is not
cured within thirty (30) days notice thereof by the Bank; or (h) the Undersigned
fails to have, at the end of each of its fiscal quarters (1) a Tangible Net
Worth of at least $300,000,000, or (2) a ratio of  Liabilities to Tangible Net
Worth of no greater than 1.0:1.0 and a default of either (1) or (2) shall not be
cured by the Undersigned within thirty (30) days.

         9.  For purposes hereof, "Tangible Net Worth" shall mean the sum of
shareholders' equity plus debt subordinated to the Undersigned's liabilities to
the Bank, minus intangibles, including, but not limited to, goodwill, customer
lists, prepaid items, deferred charges, debts owed by officers and other
affiliates and such "Other Assets" as set forth on the financial statements of
the Undersigned. "Liabilities" shall mean all liabilities of the Undersigned
that would be shown on a balance sheet of the Undersigned prepared in accordance
with generally accepted accounting principles consistently applied.

         10. Whenever the Undersigned shall be in default as aforesaid, without
demand or notice of any kind except as set forth herein, the entire unpaid
amount of all Obligations shall become immediately due and payable, and the Bank
may exercise, from time to time, any and all rights and remedies available to it
under the Uniform Commercial Code of Illinois, or otherwise, including those
available under any written instrument (in addition to this Note) relating to
any of the Obligations and may, without demand or notice of any kind,
appropriate and apply toward the payment of such of the Obligations, whether
matured or unmatured, including reasonable costs of collection and reasonable
attorneys' and paralegals' fees, and in such order of application as the Bank
may, from time to time, elect, any balances, credits, deposits, accounts or
monies of the Undersigned in possession, control or custody of, or in transit to
the Bank.

         11. THE UNDERSIGNED WAIVES THE BENEFIT OF ANY LAW THAT WOULD OTHERWISE
RESTRICT OR LIMIT THE BANK IN THE EXERCISE OF ITS RIGHTS, WHICH IS HEREBY
ACKNOWLEDGED, TO APPROPRIATE WITHOUT NOTICE, AT ANY TIME FOLLOWING DEFAULT
(AFTER GIVING EFFECT TO APPLICABLE GRACE OR CURE PERIODS, IF ANY), ANY
INDEBTEDNESS MATURED OR UNMATURED, OWING FROM THE BANK TO THE UNDERSIGNED. THE
BANK MAY, FROM TIME TO TIME, WITHOUT DEMAND OR NOTICE OF ANY KIND, APPROPRIATE
AND APPLY TOWARD THE PAYMENT OF SUCH OF THE OBLIGATIONS, AND IN SUCH ORDER OF
APPLICATION, AS THE BANK MAY, FROM TIME TO TIME, ELECT ANY AND ALL SUCH
BALANCES, CREDITS, DEPOSITS, ACCOUNTS, MONIES, CASH EQUIVALENTS AND OTHER ASSETS
OF OR IN THE NAME OF THE UNDERSIGNED, THEN OR THEREAFTER WITH THE BANK.

         12. THE UNDERSIGNED WAIVES EVERY DEFENSE, CAUSE OF ACTION, COUNTERCLAIM
OR SET OFF WHICH THE UNDERSIGNED MAY NOT HAVE OR HEREAFTER MAY HAVE TO ANY
ACTION BY BANK IN ENFORCING THIS NOTE OR ANY OF THE OTHER OBLIGATIONS, RATIFIES
AND CONFIRMS WHATEVER THE BANK MAY DO PURSUANT TO THE TERMS HEREOF AND AGREES
THAT BANK SHALL NOT BE LIABLE FOR ANY ERROR OF JUDGMENT OR MISTAKES OF FACT OR
LAW EXCEPT FOR THOSE ERRORS OR MISTAKES WHICH RESULT FROM THE BANK'S GROSS
NEGLIGENCE OR WILLFUL MISCONDUCT. THE BANK AND THE UNDERSIGNED, KNOWINGLY,
VOLUNTARILY AND INTENTIONALLY WAIVE IRREVOCABLY THE RIGHT EITHER MAY HAVE TO
TRIAL BY JURY WITH RESPECT TO ANY LEGAL PROCEEDING BASED HEREON, OR ARISING OUT
OF, UNDER OR IN CONNECTION WITH THIS NOTE OR ANY OF THE OTHER OBLIGATIONS, OR
ANY AGREEMENT, EXECUTED OR CONTEMPLATED TO BE EXECUTED IN CONJUNCTION HEREWITH
OR ANY COURSE OF CONDUCT OR COURSE OF DEALING IN WHICH THE BANK AND THE
UNDERSIGNED ARE ADVERSE PARTIES. THIS PROVISION IS A MATERIAL INDUCEMENT FOR THE
BANK GRANTING ANY FINANCIAL ACCOMMODATION TO THE UNDERSIGNED.

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         13. The Undersigned, and any other party liable with respect to the
Obligations, including any guarantors, and any and all endorsers and
accommodation parties, and each one of them, waive any and all presentment,
demand, notice of dishonor, protest, and all other notices and demands in
connection with the enforcement of the Bank's right hereunder, and hereby
consent to, and waive notice of release, with or without consideration, of the
Undersigned. No default shall be waived by the Bank except in writing. No delay
on the part of the Bank in the exercise of any right or remedy shall operate as
a waiver thereof, and no single or partial exercise by the Bank of any right or
remedy shall preclude other or further exercise thereof, or the exercise of any
other right or remedy. This Note: (I) is valid, binding and enforceable in
accordance with its provisions, and no conditions exist to the legal
effectiveness of this Note; (ii) contains the entire agreement between the
Undersigned and the Bank; (iii) is the final expression of the intentions of the
Undersigned and the Bank; and (iv) supersedes all negotiations, representations,
warranties, commitments, offers, contracts (of any kind or nature, whether or al
or written) prior to or contemporaneous with the execution hereof. No prior or
contemporaneous representation, warranties, understandings, offers or agreements
of any kind or nature, whether oral or written, have been made by the Bank or
relied upon by the Undersigned in connection with the execution hereof. No
modification, discharge, termination or waiver of any of the provisions hereof
shall be binding upon the Bank, except as expressly set forth in a writing duly
signed and delivered on behalf of the Bank.

         14. The Undersigned agrees to pay all reasonable costs, reasonable
legal expenses, reasonable attorneys fees and paralegals' fees of every kind,
paid or incurred by the Bank in enforcing its rights hereunder, including, but
not limited to, litigation or proceedings initiated under the United States
Bankruptcy Code, or in respect to any other of the Obligations, or in defending
against any defense, cause of action, counterclaim, set off or crossclaim based
on any act of commission or omission by the Bank with respect to this Note or
any other of the Obligations, promptly on demand of the Bank or other person
paying or incurring the same.

         15. TO INDUCE THE BANK TO MAKE THE LOAN EVIDENCED BY THIS NOTE, THE
UNDERSIGNED IRREVOCABLY AGREES THAT ALL ACTIONS ARISING DIRECTLY OR INDIRECTLY
AS A RESULT OR IN CONSEQUENCE OF THIS NOTE OR ANY OTHER AGREEMENT WITH THE BANK
SHALL BE INSTITUTED AND LITIGATED ONLY IN COURTS HAVING SITUS IN THE CITY OF
CHICAGO, ILLINOIS, AND THE UNDERSIGNED HEREBY CONSENTS TO THE EXCLUSIVE
JURISDICTION AND VENUE OF ANY STATE OR FEDERAL COURT LOCATED AND HAVING ITS
SITUS IN SAID CITY, AND WAIVES ANY OBJECTION BASED ON FORUM NON CONVENIENS. THE
UNDERSIGNED HEREBY WAIVES PERSONAL SERVICE OF ANY AND ALL PROCESS, AND CONSENTS
THAT ALL SUCH SERVICE OF PROCESS MAY BE MADE BY CERTIFIED MAIL, RETURN RECEIPT
REQUESTED, DIRECTED TO THE UNDERSIGNED AT THE ADDRESS INDICATED IN THE BANK'S
RECORDS IN THE MANNER PROVIDED BY APPLICABLE STATUTE, LAW, RULE OF COURT OF
OTHERWISE.

         16. The loan evidenced hereby has been made and this Note has been
delivered at the Bank's main office. This Note shall be governed and construed
in accordance with the laws of the State of Illinois, in which state it shall be
performed, and shall be binding upon the Undersigned and its successors and
assigns. If this Note contains any blanks when executed by the Undersigned, the
Bank is hereby authorized, without notice to the Undersigned, to complete any
such blanks according to the terms upon which the loan or loans were granted.
Wherever possible, each provision of this Note shall be interpreted in such
manner as to be effective and valid under applicable law, but if any provision
of this Note shall be prohibited by or be invalid under such law, such provision
shall be severable, and be deemed ineffective to the extent of such prohibition
or invalidity without invalidating the remaining provisions of this Note. If
more than one party shall execute this Note, the term "Undersigned" as used
herein shall mean all parties signing this Note and their respective successors
and assigns, and such parties shall, as the case may be, be jointly and
severally obligated hereunder.

         17. The Undersigned represents and warrants to the Bank that the
execution and delivery of this Note has been duly authorized by resolutions
heretofore adopted by its Board of Directors and in accordance with law and its
bylaws, that said resolutions have not been amended or rescinded, are in full
force and effect and that the officer or officers executing and delivering this
Note for and on behalf of the Undersigned are duly authorized so to act. The
Bank, in extending financial accommodations to the Undersigned, is expressly
acting and relying

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upon the aforesaid representations and warranties.

         18. The Undersigned acknowledges and agrees that the lending
relationship hereby created with the Bank is and has been conducted on an open
and arm's length basis in which no fiduciary relationship exits and that the
Undersigned has not relied and is not relying on any such fiduciary relationship
in consummating the loan evidenced by this Note.

         19. As used herein, all provisions shall include the masculine,
feminine, neuter, singular and plural thereof, wherever the context and facts
require such construction and in particular the word "Undersigned" shall be so
construed.

         20. This Note is in replacement and substitution for, but not a
repayment of, that certain $35,000,000 Revolving Note dated as of August 31,
2001 of the Undersigned payable to the order of the Bank and does not and shall
not be deemed to constitute a novation therefor.

         IN WITNESS WHEREOF, the Undersigned has executed this Note on the date
above set forth.

                         CDW COMPUTER CENTERS, INC.

                         By:    /s/ John A. Edwardson
                                -----------------------------------------------
                         Name:  John A. Edwardson
                         Title: Chairman & Chief Executive Officer

                         By:    /s/ Barbara A. Klein
                         Name:  Barbara A. Klein
                         Title: Senior Vice-President & Chief Financial Officer<PAGE>

                                 Exhibit 10 (b)

                            STOCK PURCHASE AGREEMENT

         Stock Purchase Agreement dated as of May 7th, 2002 (this "Agreement")
between CDW Computer Centers, Inc., an Illinois corporation, (the "Company")
and Daniel B. Kass ("Mr. Kass").

                                    RECITALS

         WHEREAS, the Company and Mr. Kass entered into a Registration Rights
Agreement dated February 5, 2001 pursuant to which Mr. Kass has certain rights
to demand one time in each of calendar years 2001, 2002 and 2003 (each, a
"Registration Demand"), that the Company repurchase or register for public sale
shares of common stock, par value $0.01 per share, of the Company ("Common
Stock"), held by Mr. Kass or acquired by him pursuant to the exercise of
certain options.

         WHEREAS, Mr. Kass delivered to the Company on April 23, 2002 a
Registration Demand covering 384,376 shares of Common Stock.

         WHEREAS, Mr. Kass desires to sell to the Company, and the Company
desires to purchase from Mr. Kass, the 384,376 shares (the "Subject Shares") of
Common Stock that are the subject of the Registration Demand, in exchange for
payment by the Company to Mr. Kass of the Purchase Price (as defined herein),
all in accordance with the terms and conditions set forth below.

         NOW, THEREFORE, in consideration of the agreements and covenants
contained herein, the parties hereto agree as follows:

                                    ARTICLE I
                               PURCHASE OF SHARES

         Section 1.01  Purchase and Sale.  Subject to the terms and conditions
of this Agreement, at the Closing (as defined herein) the Company shall
purchase from Mr. Kass, and Mr. Kass shall sell to the Company, the Subject
Shares.

         Section 1.02  Purchase Price.  The aggregate purchase price for the
Subject Shares shall be $19,026,612 (the "Purchase Price").

                                   ARTICLE II
                                     CLOSING

         Section 2.01 Closing Date. The closing (the "Closing") of the purchase
and sale of the Subject Shares shall occur on the date hereof (the "Closing
Date").

         Section 2.02  Deliveries by Mr. Kass. On the Closing Date, Mr. Kass
shall deliver or cause to be delivered to the Company one or more certificates
representing the Subject Shares, each certificate duly endorsed by Mr. Kass or
accompanied by an appropriate stock power duly executed by Mr. Kass. Mr. Kass
shall execute and deliver such further instruments and take such further actions
as may be reasonably requested by the Company to carry out the intent and
purposes of this Agreement.

         Section 2.03 Deliveries by the Company. On the Closing Date, the
Company shall deliver to Mr. Kass the Purchase Price by wire transfer to the
account designated on Exhibit A attached hereto. The Company shall execute and
deliver such instruments and take such further actions as may be reasonably
requested by Mr. Kass to carry out the intent and purposes of this Agreement.

<PAGE>

                                   ARTICLE III
                     REPRESENTATION AND WARRANTY OF MR. KASS

         Section 3.01  Title to Subject Shares. Mr. Kass represents and
warrants that he is the sole owner of the Subject Shares and that there are no
outstanding options, warrants or other rights to acquire any of the Subject
Shares. Mr. Kass further represents and warrants that the Subject Shares shall
be transferred by Mr. Kass to the Company on the Closing Date free and clear of
all liens, claims and encumbrances.

         Section 3.02 No Conflict. Mr. Kass represents and warrants that the
execution, delivery and performance of this Agreement by him does not and will
not conflict with, breach, violate or cause a default under any contract,
agreement (including any "lock-up" agreement), instrument, order, judgment or
decree to which he is a party or by which he is bound.

                                   ARTICLE IV
                   REPRESENTATION AND WARRANTY OF THE COMPANY

         Section 4.01 Authority and Enforceability. The Company hereby
represents and warrants that it has the requisite corporate power and authority
to execute this Agreement and deliver the Purchase Price, that this Agreement
has been duly authorized, executed and delivered by the Company and that this
Agreement is the legal, valid and binding obligation of the Company, enforceable
against the Company in accordance with its terms, except as the same may be
limited by bankruptcy, insolvency or other laws relating to or affecting the
enforcement of creditors' rights generally and the effect of general principles
of equity.

                                    ARTICLE V
                      COVENANTS AND AGREEMENTS OF MR. KASS

         Section 5.01 Registration Demand. Mr. Kass acknowledges and agrees that
the purchase of the Subject Shares and the payment of the Purchase Price (less
any required withholding taxes) and the performance of the Company's other
obligations under this Agreement, if any, fully satisfy the Company's
obligations with respect to the Registration Demand delivered by Mr. Kass on
April 23, 2002 pursuant to the Registration Rights Agrement and that the Company
shall have no further obligations with respect to such Registration Demand and
no obligations whatsoever with respect to any other Registration Demands made by
Mr. Kass under the Registration Rights Agreement with respect to calendar year
2002.

    Section 5.02 Lock-up Period. From the Closing Date through August 5, 2002
(the "Lock-up Period"), Mr. Kass shall not, without the prior written consent of
the Company, offer, pledge, sell, contract to sell, sell any option or contract
to purchase, purchase any option or contract to sell, grant any option, right or
warrant for the sale of, or otherwise dispose of or transfer any shares of
Common Stock, provided, however, that Mr. Kass will not be prohibited from (i)
selling additional shares of Common Stock to the Company or (ii) selling shares
of Common Stock in private sales to "qualified institutional buyers," as such
term is defined in Rule 144A under the Securities Act of 1933.

    Section 5.03 Post-Lock-up Period Rule 144 Sales. Mr. Kass agrees that he
shall execute all Rule 144 sales made by him during the period commencing at the
end of the Lock-Up Period and ending on December 31, 2003 through a broker
chosen by the Company and approved by him, provided that such approval shall not
be unreasonably withheld.

                                   ARTICLE VI
                                  MISCELLANEOUS

         Section 6.01 Assignment and Succession. The rights and obligations of
the parties under this Agreement shall inure to the benefit of and be binding
upon their respective successors and assigns.

         Section 6.02 Headings. The Article and Section headings in this
Agreement are for convenience of reference only and shall not define or limit
the provisions hereof.

<PAGE>

         Section 6.03 Applicable Law. This Agreement shall at all times be
governed by and construed, interpreted and enforced in accordance with the laws
of the State of Illinois without giving effect to the provisions, policies or
principles thereof relating to choice or conflict of laws that would result in
the application of the law of another jurisdiction.

         Section 6.04 Counterparts. This Agreement may be executed in
counterparts, each of which when so executed shall be deemed an original and all
of which shall constitute one and the same instrument.

         Section 6.05  Public Statements.  Mr. Kass and the Company shall, to
the extent practicable, consult with each other prior to making any public
statements regarding the Company's  purchase of the Subject Shares. Mr. Kass
acknowledges that the Company intends to issue a press release describing the
sale under this Agreement.

                                      * * *

<PAGE>

         In Witness Whereof, the parties hereto have executed this Agreement as
of the day and year first above written.

                            CDW COMPUTER CENTERS, INC.

                            By:     /s/ Christine A. Leahy
                               ------------------------------------
                            Name:   Christine A. Leahy
                            Title:  Vice President, General Counsel

                            /s/ Daniel B. Kass
                            ---------------------------------------
                            DANIEL B. KASS

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