on occasion my external mouse stops working. restart is the only way to return. other options?

Is your mouse wired or wireless? If it is wireless, the batteries may be low. There may also be an issue with the receiver (the small part that plugs into a USB port), or the USB port. To check, you can plug the receiver into a USB port that you know is working. If the batteries are good and the problem is not with the computer's USB port, your mouse may be defective.

If you have a wired mouse, also try a different USB port first. If the problem persists after you switch to a known working USB port, there may be faults or damage in the mouse wiring or connector.