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                                                                    EXHIBIT 10.F

                               AMENDMENT FOUR TO
                            COMPUCOM SYSTEMS, INC.
                          401(k) MATCHED SAVINGS PLAN



     WHEREAS, effective January 1, 1988, CompuCom Systems, Inc. (the "Company")
established the CompuCom Systems, Inc. 401(k) Matched Savings Plan (the "Plan")
for the benefit of employees of the Company and its affiliates; and

     WHEREAS, the Company amended and restated the Plan in its entirety
effective as of May 1, 1996, adopted Amendment One to the Plan effective as of
January 1, 1998, adopted Amendment Two to the Plan effective as of January 26,
1998, and adopted Amendment Three to the Plan effective as of May 28, 1999; and

     WHEREAS, the Company recently acquired certain assets from ENTEX
Information Services, Inc. and its affiliates ("ENTEX") as of May 10, 1999 (the
"ENTEX Acquisition"), and in connection with the ENTEX Acquisition certain
former ENTEX employees have become employees of the Company (the "ENTEX
Acquisition Employees"), and some or all of the ENTEX Acquisition Employees have
become Plan participants;

     WHEREAS, the Company desires to merge into the Plan the assets and benefit
liabilities of the ENTEX 401(k) Retirement Savings Plan (the "ENTEX 401(k)
Plan") attributable to the ENTEX Acquisition Employees and therefore must under
the Employee Retirement Income Security Act of 1974, as amended ("ERISA") and
the Internal Revenue Code of 1986, as amended (the "Code") amend the Plan to
provide the ENTEX Acquisition Employees with (i) credit for the service
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previously credited to them under the ENTEX 401(k) Plan, (ii) the higher of the
vested percentage that they had under the ENTEX 401(k) Plan or the vested
percentage that they would otherwise have under the Plan, and (iii) optional
forms of benefit required by ERISA and the Code to be protected with respect to
benefits accrued under the ENTEX 401(k) Plan;


     NOW, THEREFORE, pursuant to its authority under Section 19.1 of the Plan,
the Company amends the Plan, effective as of the date of the merger into the
Plan of the portion of the ENTEX 401(k) Plan attributable to the ENTEX
employees, as follows:

1.   The definition of "Vesting Service" in Section 1.1 is amended by adding the
following at the end thereof:

     In the case of any Employee who is a former employee of ENTEX Information
     Services, Inc. or any of its affiliates ("ENTEX") and who became or becomes
     an Employee in connection with the Employer's acquisition of certain ENTEX
     assets on May 10, 1999, for purposes of determining such Employee's vested
     interest, such Employee's period of service shall include all service
     credited or required to be credited for purposes of determining his or her
     vested percentage under the ENTEX 401(k) Retirement Savings Plan (the
     "ENTEX 401(k) Plan").

2.  Section 6.11 of the Plan is amended by adding the following sentence at the
end thereof:

     Notwithstanding the foregoing, a Participant whose account in the ENTEX
     401(k) Plan is merged into the Plan as a consequence of the Company's May
     10, 1999 acquisition of certain assets from ENTEX shall be 100% vested in
     his or her Profit Sharing and Matching Contributions Sub-Accounts, as well
     as in any other sub-account holding any portion of his or her benefit
     originally accrued under the ENTEX 401(k) Plan.

3.  The first sentence of Section 16.1 of the Plan is amended to read as
follows:

     Distribution shall be made to a Participant, or, if the Participant has
     died and the Participant's surviving spouse is the Participant's
     Beneficiary, to the Participant's surviving spouse, in a single sum
     payment.

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4.   Section 16.1 of the Plan is amended by adding the following at the end
     thereof:

     Notwithstanding the foregoing, all optional forms of benefit under the
     ENTEX 401(k) Plan required to be protected under Section 411(d)(6) of the
     Code and the regulations thereunder shall be protected as set forth in
     Appendix "A" to the Plan's Fourth Amendment.

     IN WITNESS WHEREOF, the Company has caused this instrument to be executed
by its duly authorized officer on this 29th day of July, 1999.


                                             COMPUCOM SYSTEMS, INC.


                                             By: /s/ M Lazane Smith
                                                -------------------------------
                                             Its: Sr VP Finance/CFO
                                                 ------------------------------

                                      -3-
<PAGE>

                                APPENDIX "A" TO
                              FOURTH AMENDMENT TO
                            COMPUCOM SYSTEMS, INC.
                          401(k) MATCHED SAVINGS PLAN

     The following optional forms of benefit not otherwise included under the
Plan have been identified as being included in the ENTEX 401(k) Plan and shall
be preserved. Such optional forms of benefit are preserved only for the portion
of a Participant's benefit attributable to his or her ENTEX 401(k) Plan benefit
that is merged into the Plan:

     .    Once a year withdrawals from Rollover Contributions Sub-Accounts, as
          specified in Section 13.01 of the ENTEX 401(k) Retirement Savings Plan
          (September 1, 1996 Restatement) (the "September 1, 1996, ENTEX 401(k)
          Plan Document"), which read as follows:

          13.01 - Withdrawals of Rollover Contributions

          A Participant who is employed by an Employer or a Related Company may,
          once each Plan Year, elect in writing, subject to the limitations and
          conditions prescribed in this Article, to make a cash withdrawal from
          his Rollover Contributions Sub-Account.

          The referenced limitations and restrictions prescribed in ... Article
          XIII of the September 1, 1996 ENTEX 401(k) Plan Document read as
          follows:

          13.04 - Limitations on Withdrawals Other than Hardship Withdrawals

          Withdrawals made pursuant to this Article, other than hardship
          withdrawals, shall be subject to the following conditions and
          limitations:

               A Participant must file a written withdrawal application with the
               Administrator such number of days prior to the date as of which
               it is to be effective as the Administrator shall prescribe.

               Withdrawals may be made effective as soon as reasonably
               practicable following the Administrator's receipt of the
               Participant's directions.

               A Participant who makes a non-hardship withdrawal from his
               Rollover Contributions Sub-Account prior to attaining age
               59 1/2 may not make a further withdrawal of Rollover
               Contributions under this Article during the remainder of the Plan
               Year in which the withdrawal is effective.

                                      -4-
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     .    Once a year withdrawals by post-age 59 1/2 Participants from their
          vested interests in their Employer Contributions Sub-Accounts, as
          specified in Section 13.02 of the September 1, 1996 ENTEX 401(k) Plan
          Document, which read as follows:

          13.02 - Withdrawals of Employer Contributions

          A Participant who is employed by an Employer or a Related Company and
          has attained age 59 1/2 may, once each Plan Year, elect in writing,
          subject to the limitations and conditions prescribed in this Article
          to make a cash withdrawal from his vested interest in his Employer
          Contributions Sub-Account. The maximum amount that a Participant may
          withdraw pursuant to this Section shall be an amount ("X") determined
          by the following formula:

               X=P(AB+D)-D

               For purposes of the formula:

               P=   The Participant's vested interest in his Employer
                    Contributions Sub-Account on the date distribution is to be
                    made.

               AB=  The balance of the Participant's Employer Contributions Sub-
                    Account as of the Valuation Date immediately preceding the
                    date distribution is to be made.

               D=   The amount of all prior withdrawals from the Participant's
                    Employer Contributions Sub-Account made pursuant to this
                    Section.

     .    Certain installment and term certain annuity distributions to
          Participants as specified in section 16.02 of the September 1,
          1996 ENTEX 401(k) Plan Document, which read as follows:

          16.02 - Optional Form of Payment

          A Participant, or his Beneficiary, as the case may be, may elect to
          receive distribution in one of the following optional forms of
          payment:


          (a)  Installment Payments - Distribution shall be made in a series of
               installments over a period not exceeding the life expectancy of
               the Participant, or the Participant's Beneficiary, if the
               Participant has died, or a period not exceeding the joint life
               and last survivor expectancy of the Participant and his
               Beneficiary. Each installment shall be equal in amount except as
               necessary

                                      -5-
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               to adjust for any changes in the value of the Participant's
               Separate Account. The determination of life expectancies shall be
               made on the basis of the expected return multiples in Table V and
               VI of Section 1.72-9 of the Treasury regulations and shall be
               calculated either once at the time installment payments begin or
               annually for the Participant and/or his Beneficiary, if his
               Beneficiary is his spouse, as determined by the Participant at
               the time installment payments begin. Notwithstanding any other
               provision of this Section to the contrary, a Participant may
               elect to receive distribution of this Separate Account for
               periods prior to the April 1 following the close of the calendar
               year in which he attains age 70 1/2 in a series of installments
               made pursuant to any formula elected by the Participant, without
               regard to the life expectancies of the Participant and his
               Beneficiary.

          (b)  Annuity Contract - Distribution shall be made through the
               purchase of a single premium, nontransferable annuity contract
               for such term certain and in such form as the Participant, or his
               Beneficiary, if the Participant has died shall select, provided
               however, that a Participant, or his Beneficiary, may not elect to
               receive distribution of an annuity payable for a term certain
               that exceeds his life expectancy. The terms of any annuity
               contract purchased hereunder and distributed to a Participant, or
               his Beneficiary, shall comply with the requirements of the Plan.

          (c)  A Participant may also elect a form of payment that was available
               to him under another Plan from which assets were directly
               transferred to this Plan, but only to the extent such form of
               payment was available under such other Plan.

     .    Any optional forms of benefit preserved in the ENTEX 401(k) Plan
          under the second sentence of the second paragraph of the September 1,
          1996, ENTEX 401(k) Plan Document, which read a follows:

          In addition, notwithstanding any other provision of the Plan to the
          contrary, the forms of payment and other Plan provisions that were
          available under the Plan immediately prior to the later of the
          effective date of this amendment and restatement or the date this
          amendment and restatement is adopted and that may not be eliminated
          under Section 411(d)(6) of the Code shall continue to be available
          to Participants who had an account under the Plan on the day
          immediately preceding the later of the effective date or the date this
          amendment and restatement is adopted.

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