We have an app that can run on Citrix or standalone. We put in place sometime ago code to automagically detect when run on Citrix and set a system flag. Prior to that the client services people had to manually set the flag when installing a system.

I've checked the code and it's using WTSQuerySessionInformation WIN32 API call. It appears that this API got changed to return > 1 for console sessions. So the CITRIX detection API calls don't function correctly anymore.

Anyone have a better way to detect Citrix under Vista?

Thanks