install sql server express 2005 to Vista 64

IIS on a 64 bit system runs by default the 64 bit version of the framework and SQL Server express is a 32 bit application so that is what is causing your problem since it needs the 32 bit framework to operate correctly.

There are 2 solutions:

1. Install SQL Server 2005 x64 developer edition instead of the express edition. This version however is not free so you will need to purchase a license witch luckily for us is not as expensive as a standard or enterprise license.

Or:

2. Click start > run and type: (maybe need make start.bat, and right click to run as administrator)

cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1

That will force your IIS to run in 32 bit emulated mode.

then again at run or a command prompt type:

%SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i

To register the 32 bit framework with IIS.
After that you should be able to install the larger version (x64) capable of SQL Server Express 2005 without incident.

This solution works on all x64 windows versions, including, windows XP x64, Windows Server x64 versions ans well as on all x64 Windows Vista versions including Windows Vista Business x64