Hi,
SQL Server 2005 Express is running in 32-bit mode, so I think you need to enable ASP.NET 2.0 32-bit mode on 64-bit operating system. To run the 32-bit version of ASP.NET 2.0, follow these steps:
1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to enable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
For more information, please refer to How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit version of ASP.NET 2.0 on a 64-bit version of Windows.
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