How can I find out if I have a 32-bit or a 64-bit Windows operating system?
Windows 8
  1. Slide the right side of the screen to access Settings.
  2. From the Control Panel list, click System and Security
  3. Select System
  4. The System Type header will tell you whether you are running 64 or 32-bit  



Windows 7
  1. Click Start, go to the Search box and type system.
  2. From the Control Panel list, click system .
  3. The operating system is displayed as follows:

    64-bit Operating System appears for the System type under System.

    32-bit Operating System appears for the System type under System.


Windows Vista
  1. Click Start, type system in the type Search box type system, and then from the Programs list, click system .
  2. The operating system is displayed as follows:

    64-bit Operating System appears for the System type under System.

    32-bit Operating System appears for the System type under System.


Windows XP
There are two methods to determine whether your computer is running the 32-bit or a 64-bit version of XP. If one does not work, try the other.

Method 1: View System Properties in Control Panel
  1. Click Start, and then click Run...
  2. Type sysdm.cpl and then click OK.
  3. Click the General tab.
  4. The operating system is displayed as follows:

    64-bit version: Windows XP Professional x64 Edition Version <Year> appears under System.

    32-bit version: Windows XP Professional Version <Year> appears under System.

    Note: <Year> is a placeholder for a year.


Method 2: View System Information window
  1. Click Start, and then click Run...
  2. Type winmsd.exe, and then click OK.
  3. From the navigation pane, select System Summary, and then from the  Item column, locate Processor.
  4. In the Value column, note:

    32-bit version: Processor Value starts with x86.

    64-bit version: Processor Value starts with ia64 or AMD64.