For the story author - Windows 7, misbehaving mouse cursor and it's a rollerball mouse so pretty old/unreliable anyway. I think I would have jumped into a few troubleshooting steps before re-installing an operating system.
Namely - unplug mouse, does it still jump
Yes - Delete driver and any sign of mouse from device manager
No - try another mouse
---> Fixed
Biting the hand that feeds IT
