When I want to download the driver of xbox360 controller for windows (For PC using), the web appear items as below: Select your operating system Windows XP(SP1 or higher) Windows XP(64-bit) Windows Vista (32-bit) Windows Vista (64-bit) Which item should I select? http://www.microsoft.com/hardware/gaming/download.mspx My equipments as below:: OS: XP home edition (5.1,版本2600) Service Pack2 CPU: Core2Duo 6300 1.86GHz The 64-bit means OS or CPU? How do I know that my OS is 32-bit or 64-bit?

A "64-bit CPU" is any modern Athlon X2, Intel Core 2, and some older CPUs. Those are all capable of running the 64-bit versions of Windows (and of Linux, et al).

However, unless you have specifically bought a 64-bit version of the OS, you have the 32-bit version. The 64-bit capable CPUs are still very fast at 32-bit OSes, and given that 32-bit has had some compatibility problems (drivers, etc), 32-bit is still the mainstream.

Thus, you want the Windows XP, 32-bit, version.

If you ever want to upgrade to Vista, I suggest getting the 64-bit version, if your CPU is capable of it, because the 32-bit version of Vista will not be able to play HDCP protected HD content in full resolution (for digital restrictions management reasons, not performance related).