Not sure if your installed version of Windows is 32-bit or 64-bit? One quick way to tell is by looking at information about your operating system installation in Control Panel.

Identifying your system type is also important when upgrading. If you're running a 32-bit version of Windows, upgrading to 64-bit can help unlock the full potential of your computer.

Fundamentally it comes down to the processor on your computer that will determine which version of an OS to get. While a 64-bit processor can run a 32-bit operating system, the reverse is not true.