Any error messages?
Have you un-installed the drivers in device manager?
Right click on the item and select un-install, then reboot the computer, letting xp re-install the drivers.
I recently had a keyboard issue with a Dell.
I had to download the Netropa keyboard software for the Dell keyboard. It seems that it required more than standard windows XP drivers. However, I did get an error message referring to this software.
after upgrading a PC to XP from ME the mouse and keyboard dont always work.This happens with the PS2 connection and USB.The PC is a Dell and all partitions were deleted then it was reformatted for a clean install.Everything else is fine but sometimes the mouse and keyboard work and then they dont show in device manager.Any ideas please?