The upgrade could have disabled your USB Ports. XP Pro loved doing that to me.
Control Panel > System > Device Manager
Just check it hasn't disabled your usb ports. If it has, Re-enable it...
or
Hardware like that comes with some software dont it ? Just try re-installing the software for it if it does. Failing that, Im sure USB optical mice always come with a PS2 Adapter.
My real advice.... Get 2K Pro
