No idea how to tell if my vista OS is 32 bit...
For Windows 7, and Windows Vista:
1. Open System by clicking the Start button, right-clicking Computer, and then clicking Properties.
2. Under System, you can view the system type.
For Windows XP:
1. Click Start.
2. Right-click My Computer, and then click Properties.
If you don't see "x64 Edition" listed, then you're running the 32-bit version of Windows XP.
If "x64 Edition" is listed under System, you're running the 64-bit version of Windows XP.