Something I have found true almost every time in Vista that I don't remember
having to do in XP.... I don't say it as a bad thing, just a lesson I have
learned over the past couple of weeks with Vista.

Go to Device Manager and 'scan for hardware changes' - XP was nearly
flawless about rebooting, and there magically was your new hardware device,
but Vista will not do that. You have to force Vista to scan the system for
the new hardware, i.e. changes.

I installed a new/separate/additional hard drive (internal, in a bay next to
the main drive) and tried 47 ways from Sunday to get the drive to show up.
Not in device manager, not in disc management, nowhere... reboot reboot,
blah blah blah.... finally went into device manager and did Scan For Changes
and the drive showed up immediately. Kind of a DUH moment for me.

I had to do the same thing to get a PCI card of USB ports to show up. I
suspect your mouse may be the same deal.

Tim