How do I tell if the Win7 or XP system version used by my computer is 32-bit or 64-bit?

To check the type of Windows you are using, follow the steps in one of the following two sections, depending on your operating system. .
Viewing 32-bit or 64-bit System Types in Windows 7 and Vista
Follow these steps to view the system type in Windows 7 and Vista:
Click the Windows icon (), then right-click on “Computer ”
Select “Properties” .
Find “system type” and note if your operating system is 32-bit or 64-bit. Figure 2 System Type 32 Bits and Figure 3 System Type 64 Bits:
Figure 1: System Type 32 Bits
Figure 2: System Type 64 Bits
View 32-bit or 64-bit in Windows XP System Type
Follow these steps to view the system type in Windows XP:
Click “Start” and right click on “My Computer”.
Select “Properties” .
In the "General" tab, view the Windows XP version name listed under "System". As shown in Figure 4 System Properties:
Figure 3: System Properties
If the version name contains the text "x64 Edition", the computer is installed with a 64-bit version of Windows XP.
If “x64 Edition” is not displayed, the 32-bit version of Windows XP is installed