my keyboard would at first start typing 2 letters everytime i pressed a key, instead of one. At first this was random, then after a while it happened with every key. After a little bit later my mouse starts acting up and won't left click properly. I have tried switching keyboards, i have tried playing with the keyboard settings in control panel, and i have tried to uninstall the keyboard in device manager and restart windows, but nothing works. Luckily my roomate has a laptop. ;-) any suggestions that don't involve me dumping my PC in the nearest river?
check for driver updates from the manufacturer's of the keyboard and mouse. Sounds like damaged driver files .. also make sure keyboard and mouse are clean.