<PAGE>

                                                                    EXHIBIT 10.3

                                                                    CONFIDENTIAL

                        SEPARATION AGREEMENT AND RELEASE

         This Separation Agreement and Release (the "Agreement") is made as of
February 25, 2003 by and between INSIGHT ENTERPRISES, INC., a Delaware
corporation (together with its subsidiaries, the "Company"), and MICHAEL V. WISE
(the "Employee").

                                    RECITALS

         WHEREAS, Employee has been employed by the Company pursuant to an
 Employment Agreement with the Company's subsidiary, Comark, Inc., dated as of
April 25, 2002 (the "Employment Agreement"); and

         WHEREAS, on or about October 23, 2002, the Company provided Employee
with notice of termination of the Employment Agreement, which termination is to
be effective on or about January 21, 2003; and

         WHEREAS, there is dispute regarding the amounts payable by the Company
to Employee pursuant to the Company's termination of the Employment Agreement;
and

         WHEREAS, the Company, on the one hand, and Employee, on the other hand,
have mutually agreed to terms for the termination of the employment
relationship.

                                    AGREEMENT

         NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Company, on the one hand, and
Employee on the other hand (individually referred to as a "Party" and
collectively referred to as the "Parties") hereby agree as follows:

         1.       Termination. Employee's positions as an officer and employee
                  of the Company are hereby terminated, such termination to be
                  effective as of January 23, 2003 (the "Separation Date").

         2.       Consideration.

                           (a)      Payment.

                                    (i)      Immediately after this Agreement
has been signed by both parties, the Company shall pay to Employee:

                                             (1) $300,000 in Base Salary
severance compensation pursuant to Section 6B(b) of the Employment Agreement;
and

                                             (2) $1,029 for his accrued vacation
through the Separation Date, pursuant to the Company's standard policy and
practice of paying full accrued vacation to terminated employees; and

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                                                                    CONFIDENTIAL

                                             (3) $147,252 in incentive
compensation severance pay pursuant to Section 6B(c) of the Employment
Agreement, for a gross payment to Employee upon full execution of this Agreement
of $448,281.

                                    (ii)     On the Effective Date (see Section
21 of this Agreement), the Company agrees to pay Employee:

                                             (1) $88,648 for his incentive bonus
for the fourth calendar quarter of 2002 due pursuant to Section 3(b)(1) of the
Employment Agreement; and

                                             (2) An additional $157,748 in
exchange for the release and the obligations made herein by Employee, for a
gross payment to Employee on the Effective Date of $246,396, resulting in an
aggregate gross payment to Employee pursuant to this Agreement of $694,677.
Such payment shall be made through the Company's payroll process and will be
subject to any withholdings required by law. All amounts are in U.S. Dollars.
Employee and the Company agree that Employee earned no incentive bonus pursuant
to Section 3(b)(1) of the Employment Agreement for the third calendar quarter of
2002. Except as otherwise provided herein, Employee shall have no duty to
mitigate damages in order to receive the consideration described by this
subsection, and the consideration shall not be reduced or offset by other
income, payments or profits received by Employee from any source.

                           (b)      COBRA/Benefits. Employee and each eligible
         dependent who constitutes a qualified beneficiary, as defined in
         Section 4980B(g)(1) of the Internal Revenue Code of 1986, as amended,
         will be eligible to continue benefits coverage under the Consolidated
         Omnibus Budget Reconciliation Act of 1985, as amended ("COBRA"), within
         the time period prescribed pursuant to COBRA.

                           (c)      Vesting of Stock Options. On April 25, 2002,
         Employee received a grant of stock options (the "Options") for the
         purchase of 100,000 shares of the Company's Common Stock at a strike
         price of $21.03 per share. Pursuant to Section 6B(d) of the Employment
         Agreement, the Options automatically vested on the Separation Date, and
         Employee was eligible to exercise the Options for the following seven
         trading days. Pursuant to the terms of the Options, because Employee
         did not exercise any Options within the seven trading days following
         the Separation Date, the Options automatically lapsed.

         3.       Confidential Information. Notwithstanding any provision in
this Agreement to the contrary, the confidentiality obligations provided in
Section 9 of the Employment Agreement shall continue in full force and effect.
Employee agrees that he has delivered to the Company (and has not kept in his
possession, recreated or delivered to anyone else) any and all devices, records,
data, notes, reports, proposals, lists, correspondence, specifications, drawings
blueprints, sketches, materials, equipment, other documents or property, or
reproductions of any aforementioned items developed by him pursuant to his
employment with the Company or otherwise belonging to the Company, its
successors or assigns.

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                                                                    CONFIDENTIAL

         4.       Payment of Salary. Employee acknowledges and represents that
the Company has paid all salary, wages, bonuses, accrued vacation, commissions,
stock options, and any and all other benefits due to Employee through the
Separation Date, except as otherwise provided for in this Agreement. Without
limiting the foregoing, Employee acknowledges and agrees that he holds an
aggregate of 46,140 shares of the Company's Common Stock and except as noted
herein has no further option, warrant, or similar right to acquire any
additional shares of the Company's capital stock. Employee shall have 90 days
from the Effective Date of this Agreement to submit his final request for
reimbursement of business expenses, subject to proper backup documentation and
not to exceed a total of $5,000. Except for the benefits identified herein,
Employee shall not be entitled to accrual of any other employee benefits,
including vacation benefits.

         5.       No Reinstatement or Reemployment. Employee agrees that the
Company may refuse to employ or reemploy Employee, and that doing so shall not
give rise to any claim or cause of action of any nature whatsoever, nor may any
suit be brought by Employee against Company or its agents arising out of any
such refusal to reemploy.

         6.       Release of Claims. The Parties, on their own behalf, and on
behalf of their respective heirs, family members, executors, officers,
directors, employees, investors, shareholders, administrators, affiliates,
divisions, subsidiaries, predecessor and successor corporations and assigns,
hereby fully and forever release each other and their respective heirs, family
members, executors, officers, directors, employees, investors, shareholders,
administrators, affiliates, divisions, subsidiaries, predecessor and successor
corporations and assigns, from, and agree not to sue each other concerning, any
claim described in paragraph (a), (b) or (c) below, whether presently known or
unknown, suspected or unsuspected, that either party may possess arising from
any omissions, acts or facts that have occurred up to, until and including the
Effective Date.

                           (a)      Any and all claims relating to or arising
         from the Employment Agreement, Employee's employment relationship with
         the Company or the termination of that relationship, including any and
         all claims for violation of any federal, state or municipal statute,
         including Title VII of the Civil Rights Act of 1964, the Civil Rights
         Act of 1991, the Age Discrimination in Employment Act of 1967, the
         Americans with Disabilities Act of 1990, the Fair Labor Standards Act,
         the Employee Retirement Income Security Act of 1974, The Worker
         Adjustment and Retraining Notification Act, and the Older Workers
         Benefit Protection Act.

                           (b)      Any and all claims to the effect that
         Employee purchased or otherwise received or held shares of stock of the
         Company at the request, inducement or insistence of the Company or any
         officer, director, employee or agent thereof, or as a result of
         influence of the Company (or any officer, director, employee or agent
         thereof) over Employee or that Employee would not, but for such
         request, inducement, insistence or influence, have purchased, accepted
         or held such shares of stock of the Company.

                           (c)      Any and all claims to the effect that the
         Company or any officer, director, employee or agent thereof made any
         promise or offer of payment or assistance to Employee in connection
         with any tax obligation arising from or relating to Employee's
         acquisition of the Company's stock, or relating to Employee's decision
         not to collar or

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                                                                    CONFIDENTIAL

         hedge his stock or any representation with respect to the market price
         at any time of the Company's stock.

         The Parties agree that the release set forth in this Section shall be
and remain in effect in all respects as a complete general release as to the
matters released. This release does not extend to (i) any obligations incurred
under this Agreement; (ii) any rights which Employee may have under any of the
Company's employee benefit plans; (iii) any claims Employee may have for
indemnification by the Company pursuant to the Company's by-laws or charter, any
indemnification agreement with the Company or otherwise; (iv) any claims
Employee may have for coverage under any applicable Company insurance policy,
including that providing coverage for the actions of Company directors and
officers and (v) any rights that a shareholder of the Company would have in the
absence of any employment, contractual or other interaction or relationship with
the Company.

         7.       Acknowledgment of Waiver of Claims under ADEA. Employee
acknowledges that he is waiving and releasing any rights he may have under the
Age Discrimination in Employment Act of 1967 ("ADEA") and that this waiver and
release is knowing and voluntary. Employee and the Company agree that this
waiver and release does not apply to any rights or claims that may arise under
ADEA after the Effective Date. Employee acknowledges that the consideration
given for this waiver and release is in addition to anything of value to which
Employee was already entitled. Employee further acknowledges that he has
consulted with an attorney with respect to this Agreement and that he has been
advised by this writing that (i) he has at least 21 days from the date he
receives this Agreement within which to consider this Agreement; (ii) he has at
least seven days following the execution of this Agreement by the Parties to
revoke the Agreement; and (iii) with the exception of the payment obligations
provided in subsection 2(a)(i), which obligations are effective upon full
execution of this Agreement, this Agreement shall not be effective until the
revocation period has expired. Any revocation should be in writing and delivered
by certified mail, overnight delivery, or otherwise with return receipt, to P.
Robert Moya, Esq. at the Company by the close of business on the seventh day
from the date that Employee signed this Agreement. Employee understands that,
although Employee has 21 days to consider the Agreement, Employee may accept the
terms of the Agreement at any time within those 21 days, and such acceptance
shall be deemed effective upon execution and delivery hereof by Employee.

         8.       Other Claims/Known or Unknown. The Parties represent that they
are not aware of any claims against each other except for those claims that are
released by this Agreement. Moreover, the Parties agree and represent that it is
within their contemplation that they may have claims against each other of
which, at the time of the execution of this Agreement, they have no knowledge or
suspicion, but that this Agreement extends to claims in any way based upon,
connected with or related to the matters described in paragraphs 6 and 7,
whether or not known, claimed or suspected by the Parties.

         9.       Confidentiality of Agreement. The Parties agree to use their
best efforts to maintain in confidence the existence of this Agreement, the
contents and terms of this Agreement, and the consideration for this Agreement
(hereinafter collectively referred to as "Settlement Information"), subject to
obligations under applicable law or listing agreements with The Nasdaq Stock
Market or other stock markets or exchanges. Employee agrees to take every
reasonable

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                                                                    CONFIDENTIAL

precaution to prevent disclosure of any Settlement Information to third parties,
and agrees that there will be no publicity, directly or indirectly, concerning
any Settlement Information. Employee agrees to take every precaution to disclose
Settlement Information only to those attorneys, accountants, governmental
entities and family members who have a reasonable need to know of such
Settlement Information.

         10.      Continued Effect of Employment Agreement Covenants.
Notwithstanding any provision in this Agreement to the contrary, the restrictive
covenants provided in Section 10 of the Employment Agreement shall continue in
full force and effect (i) in the case of the Covenant Not to Compete provided in
Section 10(a) of the Employment Agreement, for six months after the Separation
Date; and (ii) in the case of the Non-Solicitation covenants provided in Section
10(b) of the Employment Agreement, for one year after the Separation Date;
provided, however, that such covenants shall apply only so long as Company is
not continuously in default of its obligations to Employee hereunder or under
any other agreement, covenant or obligation.

         11.      No Admission of Liability. The Parties understand and
acknowledge that this Agreement constitutes a compromise and settlement of
disputed claims and is made to buy peace and for no other reason. No action
taken by either of the Parties hereto, or either of them, either previously or
in connection with this Agreement shall be deemed or construed to be (i) an
admission of the truth or falsity of any claims heretofore made or (ii) an
acknowledgment or admission by either party of any fault or liability whatsoever
to the other party or to any third party.

         12.      Costs. The Parties shall each bear their own costs, expert
fees, attorneys' fees and other fees incurred in connection with this Agreement.

         13.      Dispute Resolution. Notwithstanding any provision in this
Agreement to the contrary, the dispute resolution process provided in Section 11
of the Employment Agreement shall continue in full force and effect.

         14.      Authority. The Company represents and warrants that the
undersigned has the authority to act on behalf of the Company and to bind the
Company and all that may claim through it to the terms and conditions of this
Agreement. Employee represents and warrants that Employee has the capacity to
act on Employee's own behalf and on behalf of all whom might claim through
Employee to bind them to the terms and conditions of this Agreement.

         15.      No Representations. The Parties represent that they have each
had the opportunity to consult with an attorney and have carefully read and
understand the scope and effect of the provisions of this Agreement. Neither
party has relied upon any representations or statements made by the other party
hereto which are not specifically set forth in this Agreement. Without limiting
the foregoing, Employee acknowledges and agrees that he has consulted such
financial and tax advisors as he has deemed appropriate in connection with the
execution and delivery of this Agreement and that he has not relied on any
representation or warranty of either the Company or any agent of the Company
with respect to the tax effects of this Agreement. The Parties further covenant
not to sue each other, or to participate or aid in any suit or proceeding (or to
execute, seek to impose, collect or recover upon, or otherwise enforce or accept
any

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                                                                    CONFIDENTIAL

judgment, decision, award, warrant or attachment) upon any claim released by
them under paragraphs 6, 7, and 8 above.

         16.      Construction. The language in all parts of this Agreement
shall in all cases be construed as a whole according to its fair meaning and not
strictly for or against either party. The paragraph headings contained in this
Agreement are for reference purposes only and will not affect the meaning or
interpretation of this Agreement in any way. All terms used in one number or
gender shall be construed to include any other number or gender as the context
may require. The parties agree that any rule of construction to the effect that
ambiguities are to be resolved against the drafting party shall not apply in the
interpretation of this Agreement or any amendment or any exhibits thereto.
Whenever the words "include," "includes," or "including" are used in the
Agreement, they shall be deemed to be followed by the words "without limitation.

         17.      Severability. If any provision hereof becomes or is declared
by a court of competent jurisdiction to be illegal, unenforceable or void, this
Agreement shall continue in full force and effect without said provision.

         18.      Entire Agreement. This Agreement represents the entire
agreement and understanding between the Company, on the one hand, and Employee
on the other, and is the complete, final and exclusive embodiment of their
agreements concerning Employee's separation from, and compensation by, the
Company and the obligations of each Party to the other. Except as specifically
provided herein, this Agreement supersedes and replaces any and all prior and
contemporaneous agreements, representations and understandings regarding
Employee's employment with, or a termination of Employee's employment with, the
Company (including the Employment Agreement). This Agreement is executed without
reliance on any promise, warranty or representations by any party or any
representative of any party other than those expressly contained in this
Agreement. Notwithstanding the provisions of any statutory or common law
provision, this Agreement is admissible for purposes of enforcement.

         19.      No Oral Modification. This Agreement may not be altered,
amended, modified or otherwise changed in any respect or particular except by a
writing signed by Employee and a duly authorized officer of the Company.

         20.      Governing Law. This Agreement shall be governed by the laws of
the State of Illinois, without regard to the conflicts of law principles
thereof.

         21.      Effective Date. With the exception of the payment obligations
provided in subsection 2(a)(i), which obligations are effective upon full
execution of this Agreement, this Agreement is effective beginning on the eighth
day after it has been signed by both the Company and the Employee (the
"Effective Date").

         22.      Counterparts. This Agreement may be executed in counterparts,
and each counterpart shall have the same force and effect as an original and
shall constitute an effective, binding agreement on the part of each of the
undersigned.

         23.      Reliance. Employee agrees, acknowledges and represents that in
deciding to sign this Agreement (i) he has relied upon his own judgment and that
of any persons of his own choosing who have provided advice or counsel to him
regarding this Agreement; (ii) that he has had a

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                                                                    CONFIDENTIAL

sufficient period of time to consider whether to enter into this Agreement and
to consider the terms and provisions of this Agreement; (iii) that no statement
made by the Company or any of its agents that is not contained in this Agreement
has in any way unduly influenced or coerced Employee to sign this Agreement; and
(iv) that this Agreement is written in a manner that is understandable to
Employee and he has read and understood all paragraphs of this Agreement.

         24.      Voluntary Execution of Agreement. This Agreement is executed
voluntarily and without any duress or undue influence on the part or behalf of
the Parties hereto, with the full intent of releasing claims as described
herein. The Parties acknowledge that:

                           (a)      They have read this Agreement;

                           (b)      They have been represented in the
         preparation, negotiation, and execution of the Agreement by legal
         counsel of their own choice;

                           (c)      They know and understand the terms and
         consequences of this Agreement and of the releases it contains; and

                           (d)      They are fully aware of the legal and
         binding effect of this Agreement.

         IN WITNESS WHEREOF, the Company and the Employee have executed this
Separation Agreement and Release on the respective dates set forth below.

"COMPANY"                                             INSIGHT ENTERPRISES, INC.,
                                                      a Delaware corporation

Dated: February 25, 2003                              By: /s/ P. Robert Moya
                                                          ----------------------
                                                      Name:   P. Robert Moya

                                                      Title: E.V.P.

"EMPLOYEE"                                            MICHAEL V. WISE

Dated: February 18, 2003                              By: /s/ Michael V. Wise
                                                          ----------------------
                                                          Michael V. Wise

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