Summary
Web Access 7 and WebLink 7 are both 32-bit web applications. On Windows Server 2003 x64 Editions, IIS is not configured to run 32-bit web applications by default. You must manually configure IIS to use 32-bit worker processes.
However, be aware that the World Wide Web Publishing service does not support running 32-bit and 64-bit worker processes concurrently on the same server. This means that enabling IIS to run 32-bit applications on Windows Server 2003 x64 Editions will disable support for 64-bit web applications.
More Information
To enable IIS 6.0 to run 32-bit applications on 64-bit Windows
cscript.exe adsutil.vbs set W3SVC/AppPools/Enable32BitAppOnWin64 "true"
Related Links
Please see the following Microsoft Knowledge Base articles for additional information on running 32-bit web applications on 64-bit Windows.
Running 32-bit Applications on 64-bit Windows (IIS 6.0)