The Big Q is how would you know if your machine is running under 32 or 64 bit pc, well some says its simple if you spend too much for your pc means you bought a 64bit pc, since most super computers are running under 64bit, but what about those 2nd hand owners how can they make sure? here is a simple guide that will help you, this guide is applicable and tested under windows XP sp2
1. Open the “System Properties” window
# If your Start menu is configured for Classic Start menu, right-click the My Computer icon on your desktop, and click Properties.
# If your Start menu is the Windows default Start menu, click the Start button, then right-click the My Computer icon in your Start menu, and click Properties.
2. Click the Advanced tab.
3. Click Environment Variables.
# In the “System variables” list at the bottom of the Environment Variables window, look for a variable called “PROCESSOR_ARCHITECTURE”. If your PC has a 32-bit processor, this variable will have a value of “x86“. If it has a 64–bit processor this variable will have a value of “x64“.