www.download.comsearch for adaware. download that, update it, and run a full scan. in safe mode if you know how to get there, otherwise normal mode will do. unplug your internet connection while you do scan, it helps sometimes. full scan can take upwards of an hour, depending on how fast the computer is, and how long since windows was last re-installed. my pc in work the other week took an hour and a half. and it's a hugely fast pc. so i'd expect it'll take longer.
that'll cure 99% of the issues you're having. and maybe speak to your dad..
