How to figure out why .NET app runs at 32-bit on a 64-bit machine

I have a .NET app (webforms - .NET 3.5) that is running on a 64-bit server as 32-bit (I checked the IntPtr.Size result). The compilation is set to AnyCPU so I would expect that on a 64-bit machine, the app would be r开发者_运维问答un at 64-bit. There are many Third-party programs incorporated into the app, could they be causing a problem? How do I figure out why 64-bit compilation is not being done?

I would check IIS to make sure that you have installed the 64-bit version. That is what determines how the ASP.NET applications run.

32-bit on 64-bit windows http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/13f991a5-45eb-496c-8618-2179c3753bb0.mspx?mfr=true