VANGUARD WINDSOR II FUND
                     INVESTMENT ADVISORY AGREEMENT ADDENDUM

                              EFFECTIVE MAY 1, 2006

This  Addendum  amends  Section  1.1 of  Schedule A of the  Investment  Advisory
Agreement dated January 1, 2006 between Vanguard Windsor Funds (the "Trust") and
Armstrong Shaw Associates Inc. ("ASA," or the "Advisor") for the management of a
portion of  Vanguard  Windsor II Fund (the  "Fund"),  a series of the Trust,  as
follows:

A. AMENDMENT

1.1.  CALCULATION  OF THE BASE FEE. The Base Fee for each fiscal  quarter of the
Fund is calculated by multiplying an Annual Percentage Rate (shown below) to the
average daily net assets of the ASA Portfolio  during such fiscal  quarter,  and
dividing  the result by four.  The  Fund's  fiscal  quarter  ends are the months
ending January, April, July, and October.


In the event of termination of this Agreement,  the fee provided in this Section
for the period beginning on the first day of the then-current fiscal quarter and
ending on the last business day on which this Agreement is in effect (the "Short
Quarter") shall be calculated by applying the foregoing annual  percentage rates
to the average daily net assets of the ASA Portfolio  during the Short  Quarter,
dividing the result by four, and multiplying that figure by a ratio equal to the
number of days in the Short  Quarter  divided by the total number of days in the
full quarter.

B. MISCELLANEOUS

Except as specifically amended hereby, all of the terms and conditions of the
Investment Advisory Agreement are unaffected and shall continue to be in full
force and effect and shall be binding upon the parties in accordance with its
terms.

ARMSTRONG SHAW ASSOCIATES INC.                  VANGUARD WINDSOR FUNDS

Monica C. Grady                 6/8/06          John J. Brennan       6/5/06
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Signature                       Date            Signature               Date


MONICA C. GRADY                                 JOHN J. BRENNAN
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Print Name                                      Print Name