amnishaw

I had this problem for the first time today on Windows 7 32-bit (x86), and I didn't have to delete any kind of registry -- Just simply go to Properties on your steam.exe, and there will be a button on the Compatibility tab that will change it for all users. If you are not an admin account, however, I don't think you can make that change. If that simple step doesn't work, then you can try the registry step, but sometimes its not necessary.