Windows 8.1: Determining 32-bit or 64-bit

General Information

This information has to do with the way the computer processes information in the CPU. 64-bit can handle large amounts of RAM more effectively. To determine whether you are using a 32-bit or a 64-bit Operating System, follow the steps below.
 

Determine 32-bit or 64-bit Operating System

1. Basic information about your computer can be found in the System window. Below are two ways to get to the System window:

• Open the Windows Charms bar [Windows Button +C]:

  • Click Settings.

  • Click Control Panel.

  • Click System.

• OR  One of the following keyboard shortcuts:

  • [Windows Button + Pause/Break]

  • [Windows Button + X] Select System

2. Locate the area named: System type.

3. If your computer is a 32-bit Operating System, you will see:

• 32-bit Operating System, x64-based processor.

4. If your computer is a 64-bit Operating System, you will see:

• 64-bit Operating System, x64-based processor.

Referenced from: Windows.microsoft.com