Try a repair of avast. Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button and scroll down to Repair, click next and follow. You may need to reboot after the repair.

If that doesn’t work you may need to download the full virus database update, the repair function should say if that is required.

  • Avast! Manual Virus Definitions Update Download - avast! Virus Definitions Update - Manual Download VPS Update (virus definitions, vpsupd.exe, approx 36MB). - 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.

Note: Ignore the file name in the images of the page that is displayed after clicking the download link, they are for the main program, not for vpsupd.exe which will be downloaded.