Windows 8 - Problems with optical USB mouse driver lost

I use Windows 8 on my laptop and following a “crash” I have lost the use of the optical USB mouse. The touch pad works fine but in “Device Manager” under “Mice and Other Pointing Devices” the properties for the touchpad is showing but not the mouse.

I have limited knowledge of computers but think that I have “lost” the mouse driver and need to know how to reinstall it.

Please would Forum users be kind enough to advise how I may best do this?

Many thanks

David