How do I know if an OS is running 32bit or 64bit?

Windows 10:

1. Open System by clicking the Start button, right-clicking Computer, and then clicking Properties.

2. Under System, you can view the system type.

Windows 8:

1. Method 1: View the System window in Control Panel

2. Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.

3. Type system in the search box, and then tap or click Settings.

4. Tap or click System.

5. If you are running a 64-bit version of Windows 8, 64-bit Operating System is displayed in the System type field under the System heading. If you are running a 32-bit version of Windows 8, 32-bit Operating System is displayed in the System type field under the System heading.

Windows 7:

1. Click Start button, then type system in the Start Search box, and then click system in the Programs list.

2. The operating system is displayed as follows:

For a 64-bit version operating system, 64-bit Operating System appears for the System type under System.

For a 32-bit version operating system, 32-bit Operating System appears for the System type under System.