Which version of the Windows operating system am I running?
  1. Click the Start button
  2. Type winver in the search box, and then press Enter.
    Note
    If the steps above don't work on your computer, you might be running a previous version of Windows. To check,
    • Click Start
    • Click Run
    • Type winver
    • Press Enter.
 
Is my PC running the 32-bit or 64-bit version of Windows?
Computers running Windows XP
  1. Click the Start button
  2. Right-click My Computer
  3. Click Properties.
  • If "x64 Edition" is listed under System, you’re running the 64-bit version of Windows XP.
  • If you don’t see "x64 Edition" listed under System, you’re running the 32-bit version of Windows XP.
  • The edition of Windows XP you're running is displayed under System near the top of the window.

Computers running Windows Vista or Windows 7

  1. Click the Start button
  2. Right-click Computer
  3. Click Properties.
  • If "64-bit Operating System" is listed next to System type, you’re running the 64-bit version of Windows Vista or Windows 7.
  • If "32-bit Operating System" is listed next to System type, you’re running the 32-bit version of Windows Vista or Windows 7.
  • The edition of Windows Vista or Windows 7 you're running is displayed under Windows edition near the top of the window.
 
How do I find my operating system version on a Mac?
  1. From the Apple menu, select About This Mac.

The resulting window shows your operating system version. In this example, you are using Mac OS X 10.5.3.