<PAGE>

                                                                  EXECUTION COPY


                           AMENDMENT NO. 3, dated as of May 30, 2002 (this
                  "Amendment"), in respect of the Credit Agreement dated as of
                  July 16, 1999, as amended and restated as of July 17, 2000 (as
                  heretofore amended, the "Credit Agreement" and, as amended by
                  this Amendment, the "Amended Credit Agreement"), among
                  Gartner, Inc. (the "Borrower"), the Lenders party thereto and
                  JPMorgan Chase Bank, as Administrative Agent (in such
                  capacity, the "Administrative Agent").

         The Borrower has requested that the Credit Agreement be amended to
effect the amendments set forth below, and the parties hereto are willing so to
amend the Credit Agreement. Each Capitalized term used but not defined herein
has the meaning assigned thereto in the Amended Credit Agreement.

         In consideration of the premises and the agreements, provisions and
covenants herein contained, the parties hereto hereby agree, on the terms and
subject to the conditions set forth herein, as follows:

         SECTION 1. Amendments. Upon the effectiveness of this Amendment as
provided in Section 3 below, the Credit Agreement shall be amended as follows:

                  (a) Section 6.01(f) (A) of the Credit Agreement is hereby
         amended by replacing the amount "$10 million" therein with the amount
         "$15 million".

                  (b) Section 6.05 of the Credit Agreement is hereby amended by
         deleting "and" from the end of clause (c) thereof, replacing the period
         at the end of clause (d) thereof with "; and", and inserting the
         following clause at the end thereof:

                           "(e) the sale by the Borrower of its ownership
                  interest in the SI Venture Fund."

                  (c) Section 6.08 of the Credit Agreement is hereby amended by
         replacing the phrase "after the Initial Effective Date does not exceed
         $50 million" in clause (vii) therein with the phrase "after May 29,
         2002 does not exceed $50 million".



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         SECTION 2. Representations and Warranties. The Borrower represents and
warrants as of the date hereof to each of the Lenders that:

         (a) Before and after giving effect to this Amendment, the
representations and warranties set forth in the Credit Agreement and the other
Loan Documents are true and correct in all material respects with the same
effect as if made on the date hereof, except to the extent such representations
and warranties expressly relate to an earlier date.

         (b) Immediately before and after giving effect to this Amendment, no
Event of Default or Default has occurred and is continuing.

         SECTION 3. Conditions to Effectiveness. The amendments set forth in
Section 1 of this Amendment shall become effective, as of the date hereof, on
the date (the "Amendment Closing Date") on which the Administrative Agent shall
have received (a) counterparts of this Amendment that, when taken together, bear
the signatures of the Borrower, the Administrative Agent, the Subsidiary Loan
Parties and the Required Lenders, (b) an amendment fee, for distribution to each
Lender that has returned a signed counterpart of this Amendment to the
Administrative Agent or its counsel by 5:00 p.m. New York City time on May 30,
2002, equal to 0.125% of the aggregate Commitments of each such signing Lender
and (c) payment of all fees and expenses (to the extent invoiced prior to the
Amendment Closing Date) payable to JPMorgan Chase Bank and J.P. Morgan
Securities Inc. in connection with this Amendment. The provisions of Section 1
shall terminate and cease to be of any force or effect if the Amendment Closing
Date shall not have occurred on or prior to June 5, 2002.

         SECTION 4. Agreement Except as specifically stated herein, the
provisions of the Credit Agreement are and shall remain in full force and
effect. As used therein, the terms "Credit Agreement", "herein", "hereunder",
"hereinafter", "hereto", "hereof" and words of similar import shall, unless the
context otherwise requires, refer to the Amended Credit Agreement. The
Subsidiary Loan Parties are executing this Amendment to confirm that their
obligations under the Guarantee Agreement, the Pledge Agreement and the
Indemnity, Subrogation and Contribution Agreement remain in full force and
effect with respect to the Amended Credit Agreement and all references in the
Guarantee Agreement, the Pledge Agreement and the Indemnity, Subrogation and
Contribution Agreement to the Credit


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Agreement shall hereafter be deemed to refer to the Amended Credit Agreement.

         SECTION 5. APPLICABLE LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

         SECTION 6. Counterparts. This Amendment may be executed in two or more
counterparts, each of which shall constitute an original but all of which when
taken together shall constitute but one contract.

         SECTION 7. Expenses. The Borrower agrees to reimburse the
Administrative Agent for all reasonable out-of-pocket expenses incurred by it in
connection with this Amendment, including the reasonable fees, charges and
disbursements of Cravath, Swaine & Moore, counsel for the Administrative Agent.

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                         IN WITNESS WHEREOF, the parties hereto have caused this
         Amendment to be duly executed by their respective authorized officers
         as of the day and year first written above.


                                             GARTNER, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             COMPUTER AND COMMUNICATION
                                             INFORMATION GROUP, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             DATAQUEST INCORPORATED,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             GARTNER (KOREA) INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             DECISION DRIVERS, INC,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

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                                             GARTNER FUND I, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             GARTNER ENTERPRISES LTD.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             GARTNER SHAREHOLDINGS INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             G.G. GLOBAL HOLDINGS, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             G.G. CREDIT INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             G.G. WEST CORPORATION,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             GRIGGS-ANDERSON, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary



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                                             THE RESEARCH BOARD, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             THE WARNER GROUP,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             VISION EVENTS INTERNATIONAL,
                                             INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Secretary

                                             G.G. CANADA, INC.,

                                               by    /s/ CATHY SATZ
                                                  ------------------------------
                                                  Name:  Cathy Satz
                                                  Title: Assistant Secretary

                                             JPMORGAN CHASE BANK,
                                             individually and as
                                             Administrative Agent,


                                               by    /s/ T. DAVID SHORT
                                                  ------------------------------
                                                  Name:  T. David Short
                                                  Title: Vice President

<PAGE>



                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    CREDIT SUISSE FIRST BOSTON

                                    By /s/ ROBERT HETU
                                      ------------------------------------------
                                      Name: ROBERT HETU
                                      Title: DIRECTOR


                                    By /s/ MARK HERON
                                      ------------------------------------------
                                      Name: MARK HERON
                                      Title: ASSOCIATE


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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    Fleet National Bank
                                    --------------------------------------------

                                    by /s/ LARISA B. CHILTON
                                      ------------------------------------------
                                      Name: LARISA B. CHILTON
                                      Title: VICE PRESIDENT



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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    The Bank of New York
                                    --------------------------------------------

                                    by /s/ MELINDA A. WHITE
                                      ------------------------------------------
                                      Name: Melinda A. White
                                      Title: Vice President



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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 24, 2002


                                    Name of Institution

                                    Wachovia Bank, NA
                                    --------------------------------------------

                                    by /s/ ELIZABETH WITHERSPOON
                                      ------------------------------------------
                                      Name: Elizabeth Witherspoon
                                      Title: Vice President



<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    IBM Credit Corporation
                                    --------------------------------------------

                                    by /s/ THOMAS S. CUCCIO
                                      ------------------------------------------
                                      Name: Thomas S. Cuccio
                                      Title: Manager of Credit



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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    [ILLEGIBLE]
                                    --------------------------------------------

                                    by /s/ RONNIE PALMER
                                      ------------------------------------------
                                      Name: Ronnie Palmer
                                      Title: Bank Officer

                                    by /s/ MICHAELA KLEIN, 212
                                      ------------------------------------------
                                      Name: MICHAELA KLEIN, 212
                                      Title: SENIOR VICE PRESIDENT





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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    Bank One, NA (Main Office Chicago)
                                    --------------------------------------------

                                    by /s/ JEFFREY LEDBETTER
                                      ------------------------------------------
                                      Name: Jeffrey Ledbetter
                                      Title: Director


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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    COMERICA BANK
                                    --------------------------------------------

                                    by /s/ JOHN M. COSTA
                                      ------------------------------------------
                                      Name: John M. Costa
                                      Title: First Vice President


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                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    MIZUHO CORPORATE BANK, Ltd.
                                    --------------------------------------------

                                    by /s/ ANDREAS PANTELI
                                      ------------------------------------------
                                      Name: Andreas Panteli
                                      Title: SVP


<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    SunTrust Bank
                                    --------------------------------------------

                                    by /s/ KAREN C. COPELAND
                                      ------------------------------------------
                                      Name: Karen C. Copeland
                                      Title: Vice President


<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    DEUTSCHE BANK AG NEW YORK BRANCH
                                    AND/OR CAYMAN ISLANDS BRANCH


                                    by /s/ DAVID G. DICKINSON, JR.
                                      ------------------------------------------
                                      Name: David G. Dickinson, Jr.
                                      Title: Vice President

                                      /s/ CHRISTOPHER S. HALL
                                      ------------------------------------------
                                      Name: Christopher S. Hall
                                      Title: Managing Director

<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    CITIZENS BANK OF MASSACHUSETTS
                                    --------------------------------------------

                                    by /s/ WILLIAM M. CLOSSEY
                                      ------------------------------------------
                                      Name: William M. Clossey
                                      Title: Assistant Vice President


<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    THE BANK OF NOVA SCOTIA
                                    --------------------------------------------

                                    by /s/ TODD S. MELLER
                                      ------------------------------------------
                                      Name: TODD S. MELLER
                                      Title: MANAGING DIRECTOR


<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Name of Institution

                                    PEOPLE'S BANK
                                    --------------------------------------------

                                    by /s/ DAVID K. SHERRILL
                                      ------------------------------------------
                                      Name: David K. Sherrill
                                      Title: Vice President


<PAGE>

                                    Signature Page to GARTNER, INC.
                                    Amendment No. 3 dated as of
                                    May 30, 2002


                                    Banco Espirito Santo S.A., Nassau Branch


                                    By /s/ ANDREW M. ORSEN
                                       -----------------------------------------
                                       Name:  Andrew M. Orsen
                                       Title: Vice President


                                    By /s/ TERRY R. HULL
                                       -----------------------------------------
                                       Name:  Terry R. Hull
                                       Title: Senior Vice President