KB31979: "HTTP 500 internal server error" error occurs when launching MicroStrategy Web

SYMPTOM:
When accessing the Strategy Web interface, an error 'HTTP 500 - Internal Server error' occurs. Turn off the Internet Option of 'Show friendly HTTP error messages', a new error message is generated as
 

'%1 is not a valid Win32 application'.

 
Additional configuration:

• 64 bit Windows Operating System
• IIS 6
• ASP.NET 2.0

CAUSE:
Switch the IIS Server between 32-bit and 64-bit, it assigns 32-bit instead of 64-bit. IIS 6.0 supports both the 32-bit and the 64-bit mode. However IIS 6.0 does not support running both modes at the same time on a 64-bit version of Windows.
 
ACTION:
Perform the following steps to reset the .NET assignment to resolve the issue:

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to disable the 32-bit mode:
   
   
    
   

   
   cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 0

   
   
   
   
3. Type the following command to install the version of ASP.NET 2.0 and to install the script maps at the IIS root and under:
   
   
   
    
   
   

   
   %SYSTEMROOT%\Microsoft.NET\Framework64\v2.0.50727\aspnet_regiis.exe -i 

   
   
   
   
   
   
4. Make sure that the status of ASP.NET version 2.0.50727 is set to Allowed in the Web.
   
   
   

For further information of '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', please refer to Microsoft website: http://support.microsoft.com/kb/894435