How to determine whether your Windows XP is 32-bit or 64-bit? You need to know when you want to install certain software.
Problem is that in 32-bit systems they don’t show it explicitly; that is if you have a 32 bit system you won’t see 64 anywhere 
. However, with Vista they display whether you’re on 32-bit or 64-bit.
You can find whether you’re using 32-bit or 64-bit system in a few easy steps.
Go to the control panel and pick the category Performance and Maintenance.
Then select system
In the General Tab of the dialog that appears
- If you see Microsoft Windows XP Professional Version Year under System, you have a 32-bit system
- If you see Microsoft Windows XP Professional x64 Edition Version Year under System, you have a 64-bit system
And that’s it.
