First of all, restart your computer and see if the issue is fixed or not. If the problem was occurring due to a minor glitch, it will be fixed automatically after restarting your computer. Also, ...
I have a USB IBM optical scroll mouse. Previously I used an adapter so I could plug it into a PS/2 port. Somehow the adapter got a bent spoke, so I've been actually plugging it into a usb port instead ...
It's not uncommon for USB ports to stop working properly; swap to a different port and change USB cables to troubleshoot. You can also use Device Manager in Windows ...