Computers that use Windows XP 32-Bit or 64-Bit editions generally work the same across the board for many users. However, for power users -- gamers, video editors and professionals who conduct business on a PC -- knowing if the machine is equipped with faster 64-Bit capabilities is just as important as the processor or graphics card. Specifically, the Windows XP 64-Bit operating system can support many more sticks of random access memory (RAM) over the 32-Bit edition, which is limited to about four 1-gigabyte sticks. You can determine the edition of your Windows XP, without having to take it apart and count the memory sticks.
Click the "Start" button in the bottom left corner of the desktop. Right-click on the "My Computer" icon from the Start menu. Select "Properties" to open a dialogue box.
Click the "General" tab.
Look for the section labelled "System." If the operating system information includes details about "x64 Edition," then the PC is running XP 64-Bit. If "x64 Edition" does not appear in that section, then the PC is running XP 32-Bit.
Although you might only have the XP 32-Bit version, you can make changes in the Windows operating system that might marginally to significantly increase the speed and performance of your PC.