How do I know which Windows bit count (32 or 64) I have?

XP Click Start, and then click Control Panel.


Then open System.
Then the System Properties opens.
For a 64-bit version operating system: Windows XP Professional x64 Edition Version < Year> appears under System.
For a 32-bit version operating system: Windows XP Professional Version <Year> appears under System.
Note <Year> is a placeholder for a year.
Vista and 7

Click Start, and then click Control Panel.

Then open System.


The operating system information is displayed as follows:
The bit version is listed on the right of System type:

Posted in: Hardware/OS,OIT HelpDesk - Knowledgebase