Mouse only working in top left quadrant

[woff3212]

I have recently downloaded and installed El Capitan and ever since I did, my mouse is only working in the top left quadrant. I have restarted multiple times, but have not been able to get this issue resolved. Any help and guidance would be greatly appreciated!

 

[Rodan52]

What computer model, what year, what mouse?

 

[desertman]

... what kind of monitor, one monitor or multiple monitors?

Have you tried to forcibly relaunch the Finder (Apple Symbol - Force Quit Applications - Finder - Relaunch)?