When installing ProClarity on 64 bit IIS, ProClarity will set IIS and app pools to 32 bit mode. The following article will guide you with disable 32 bit mode .

http://support.microsoft.com/kb/894435

ASP.NET 2.0, 64-bit version

To run the 64-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 disable the 32-bit mode:

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