Format and reinstall to solve the problem.
Then:
After installing core softwares that you always use. Take a full backup. I mean ghost image of the hardware. You may use Norton Ghost.
As a protection:
- Do not use Norton Anivirus or Systemworks
- Do not use Internet Explorer
- Do not use Kazaa or Emula or smiliar P2P sowftware
- Use thrustworthy antivirus and spy detector softwares.
