Using Windows XP on Dell computer, 512 mb RAM. With no programs running I can occaisionally hear what I think is the hard drive "bogging down" (clicking noises also). In Task Manager, there appears a sharp spike in performance, and up to 100% of CPU is used briefly. The spike is so sharp it's hard to tell what process might be doing this as I can't get the processes tab on the TM open fast enough. Even if I figured out a likely process, what would the next step be? When it happens, and sometimes at other times, the cursor jumps to another part of the screen. It may jump several times in one occurence. Anyone have an idea what's going on? This happened with old Intellimouse, andwith new Microsoft optical mouse as well. Both appeared to be in clean condition.