avast antivirus problem

There's a problem with a avast antivirus Ive taken a full system scan 1 hour long the result was
"Some files could not be scanned".
So I go into my control panel.
And clicked the update, after that I clicked repair. So I
took another avast antivirus full system scan,
this one was 30 minutes, it said the same result...
"Some files could not be scanned". So, im just hoping one of you guys can help me out?
Also, I cannot apply the following action's:
Repair, Move to chest, Delete, Do nothing

(Nevermind uninstalled avast)

Could be the files are password protected.

Is there any more information in the error message?

Although the issue is moot for the thread-starter, for others searching this thread:  I've used Avast AV for some time, and numerous files could not be scanned, 'cause such were inside of password-protected archives -- that was the most common reason I got.  This is very normal behavior for Avast and other AV products.