A slightly more accurate way of detecting 64-bit windows is to look for folder %SystemRoot%\SysWOW64 (commonly Windows\SysWOW64) since it contains the binaries windows uses to launch 32-bit applications it should not be present on 32-bit windows installations.This is a little more accurate than checking for Program Files (x86) because I recall seeing an installation option somewhere in Windows Vista which allows that folder to be renamed, but I've never seen one for SysWOW64.