I suddenly got a message saying the Windows does not recognise the last device I installed. I have not installed any new devices. However my wireless mouse stopped working. I fiddled around switching on and off but still no joy. Eventually I unplugged the usb for the mouse and reinserted it. Then I got a message saying that Windows was installing the device and now my mouse works. Anyone know why this happened?
All sorts of things can corrupt the data on your computer, from local power surges to radiation from the sun, so it's not particularly surprising when a registry entry gets corrupted. In this case it seems likely that the one telling your computer which driver to use in association with your wireless mouse went AWOL for some reason.
Unless it keeps happening there's nothing to worry about.