Question - How do I determine if I have 64-bit vs. 32-bit CPU?
Answer -
Determine Windows version
If you're wanting to determine the type of version of Windows your computer is running follow the below steps for your version of Windows. Keep in mind that a 64-bit processor can be using either 32-bit or 64-bit version of Windows and that a 32-bit processor can only use a 32-bit version of Windows.
Microsoft Windows XP users
Press and Hold the Windows Key and the Pause key or open the System icon in Control panel.
In the General tab of the System Properties window if your computer says Windows XP you're running the 32-bit version of Windows. If the computer is saying Windows XP Professional x64 Edition you're running the 64-bit version of Windows XP.
Microsoft Windows Vista users
Press and Hold the Windows Key and the Pause key or open the System icon in Control panel.
In the System window by System Type you'll have 32-bit Operating System if you're running a 32-bit version of Vista and 64-bit Operating System if you're running the 64-bit version.