Possible Hacker

[imported_Wicked Steve]

In general, messing with someone's personal computer is about at the bottom of a CRacker's priority list (and a hacker is busy programming, not causing trouble) - they'd sooner just write a virus that would make it look like your computer was being controlled. Unless you know specific people who would be likely (and able) to access your computer, it's almost certain that your problem was caused by something else.

And if someone got into your system once, wiping the hard drive is not going to prevent them from doing it again. For that (and I wouldn't bother) you need a firewall.