|PS/2 or USB mouse? |
If PS/2, are you powering down the computer and then connecting the new mouse?
If the mouse works on one PC and not the other then there could be an issue with the port. I'm not really sure how to fix a PS/2 port issue, I've never had one go bad. Perhaps the answer is to use a PS/2 to USB adapter to plug the mouse into a USB port.
If it's a USB mouse try using another USB slot. If you get the same results from all of the USB slots try updating your USB drivers. I use www.driveragent.com for EVERYTHING. It's a fantastic site though you have to pay for it.
You might also just unistall your USB ports through Device Manager and let Windows reload them on the next boot. That idea can be tricky though so don't go out of your way to do it.
Let us know what works.