I just installed Adobe Photoshop cs6 and cs6 (64 bit) on Windows 7, which should I use?
The 64 bit version should be used most of the time.
The 32 bit version is installed for legacy reasons since some 32 bit plugins have not been updated to 64 bit.
If you ever need to run 32 bit only plugins then you would use 32 bit Photoshop.
Europe, Middle East and Africa