Cannot run succesfully Smart Scan

Hi

I run registered Avast Internet Security on my PC under Windows XP.

Until two weeks ago I could ran Smart Scan successfully just as all other types of scanning, which I do regularly. This week, however, my Smart Scan runs up to around 69%, then suddenly stops with a message : The Scan was stopped and underneath an underlined statement saying: Start scan again with a biggish Circle Sign on top of it, in red color!

What could be the problem and how to solve it?

Your help will be highly appreciated.

Repair Avast:

  1. Control Panel → Add/Remove programs → Avast
  2. Click on ‘Repair’.
  3. Follow instructions.
  4. Reboot.