FIX: You receive an error message when you try to install the original release version of SQL Server 2005 or SQL Server 2005 Service Pack 1 on a computer that is running Windows Vista
The following pages were recently modified.
Source: Knowledge Base
Product: Microsoft SQL Server 2005 Enterprise Edition, SQL Server 2005 Enterprise X64 Edition & SQL Server 2005 Standard Edition
Notification Contents: New and Major Modifications
FIX: You receive an error message when you try to install the original release version of SQL Server 2005 or SQL Server 2005 Service Pack 1 on a computer that is running Windows Vista
http://support.microsoft.com/kb/932593/en-US