EXHIBIT 10(mm)

                            STOCK PURCHASE AGREEMENT

         Stock   Purchase   Agreement   dated  as  of  February  2,  2001  (this
"Agreement") between CDW Computer Centers,  Inc., an Illinois corporation,  (the
"Company") and Daniel B. Kass ("Mr. Kass").


                                    RECITALS

         Whereas,  the Company  desires to purchase from Mr. Kass,  and Mr. Kass
desires to sell to the Company,  318,182 shares (the "Subject Shares") of common
stock,  par value  $0.01 per share,  of the Company  (the  "Common  Stock"),  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 $12,225,506.99 (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 first  business day following
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.



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                                   Article III
                     Representation and Warranty of Mr. Kass

         Section 3.01 Title to Subject Shares. Mr. Kass is the sole owner of the
Subject Shares.  There are no outstanding  options,  warrants or other rights to
acquire any of the Subject  Shares.  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.

                                   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  (by  action of the Board of  Directors,  following  a
recommendation from an independent committee of outside directors), 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 of Mr. Kass

         Section 5.01 Lock-up Period.  From the Closing Date through May 3, 2001
(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 5.02  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.

         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.




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         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/ Harry J. Harczak, Jr.
                                         -------------------------
                                  Name:  Harry J. Harczak, Jr.
                                  Its:   Chief Financial Officer,
                                         Treasurer and Secretary

                                         /s/ Daniel B. Kass
                                         -------------------------
                                         Daniel B. Kass