Unscanned files

Hi Guys,
I notice that each time I scan there are a number of unscanned files, and that the number is increasing.
Can anyone please explain to me what these are, and are they detrimental to my system?
If so, can I remove them, and how?

Many thanks.
Andrew.

Some common examples of the file name, location and reason why they weren’t scanned would help ?

Most common are those that are password protected.

That said files that can’t be scanned are just that, not an indication that they are infected, suspect or corrupt. In any case there is little that a user can do about files that can’t be scanned, all avast is doing is making you aware of files that can’t be scanned.