you’re right. so maybe it’s better to do this:

after the scan is completed avast must show a detailed
report showing which files/directories couldn’t be read.

(stopping the scan without giving detailed informations
is useless: what should do a user do when “5= access denied”
is showed on the screen ?)

then avast could ask the user what to do:

  1. skip that files and stop the scan?
  2. let the user try to fix permission and rescan only that files?
  3. try to fix permissions by itself ?

in the last case avast when run by an administrator could:

  1. save permissions
  2. add additional permission to be able to scan files
  3. restore original permissions

I 've seen that norton skips c:\system volume information,
it could be useful to see how other av work.

comments ?