Have you tried testing things with a corded mouse? Also, have a look in your task manager (Ctrl + Alt + Del) to see if a program is running which is hogging all your resources. If your CPU is up to 100% in the Performance tab, have a look on the Processes tab to see what's doing it. You may have contracted some spyware from somewhere, or it maybe a genuine program having difficulties. If you find something, use End Task to close it, and see if that cures things.