Did you try the repair first, that may be enough, we can cross other bridges as we come to them. Of course you can take the reinstall route, but generally we suggest the lessor hassle of the options.

  • Avast! Manual Virus Definitions Update Download - avast! Virus Definitions Update - Manual Download ensure that you select the correct virus definitions (for avast 5, vpsupd.exe, approx 31MB). - Save the file to your hard disk, locate where you saved it and double click it and that should carry out the virus definitions update.