System restore stopped avast from working

So I had Avast free antivirus for about a year, then I started having issues with my computer so I used the system restore. But now when I tried to use Avast it comes up with one of two warnings, one says that the Avast service is not running, and when I try to remove the program it says that there is an error and that the set up can’t continue. I just recently bought the Pro Antivirus version hoping that it would overwrite the damage I caused and install the newer version, however, it won’t install and I’m out of ideas. Anyone have any advice?

  1. Download avast! Pro Antivirus: http://files.avast.com/iavs5x/avast_pro_antivirus_setup.exe
  2. Follow instructions: http://www.avast.com/uninstall-utility (Run this tool for all prior installed avast! versions…!!)
  3. Reinstall avast! with the downloaded installer from point 1.
  4. Reboot.