Several topics about this already.
For those of you who are are using the regular release version 7.0.1466, and the repair failed - 'Error processing packages. Please use full update.' - then this worked for me on my win7 netbook with 7.0.1466:
Then you will need to do a Manual update of VPS -
avast! Virus Definitions Update - Manual Download VPS Update (virus definitions, vpsupd.exe, approx 67.5 MB). - 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.
If you don't want to go through that process, then wait for the avast team to resolve it, which hopefully won't take too long.