Connect the PS2 mouse. Power-on the computer. XP should install the mouse device after boot- and it may require a re-boot. If your mouse came with software, you can install it. Most generic mouse software I have seen is pretty basic, it may put a mouse icon in the system tray so you can change various settings, and it may provide additional cursor selections than XP's vanilla-flavored ones. Gaming mice usually have drivers and additional hardware settings you can access, including progamming the various mouse buttons.