<<...when unistalling the first instance would disable the mouse itself?>>
I had that thought at one time
, but it doesn't work that way.
Go ahead and uninstall them...both will work properly until reboot...at which time they will be uninstalled properly...and then reinstalled as XP boots up. The same thing happens when you uninstall video drivers...the function continues long enough for the user to reboot and then it starts all over.