64bit Checker is a free small portable tool that runs on Windows 7, Vista, XP, 2000, NT andWindows Me, 98, 95. Download it from http://www.igorware.com/64bit-checker
It will gives you following details
- what version of Windows is installed on your computer,
- is it 64bit or 32bit version of Windows
- is your processor capable of running 64bit operating systems.