Files can't be scanned - Cannot be accessed by the system

[Cokomon]

So I just ran a quick scan and found in the results that some of the files couldn't be scanned.  I've run into the issue before, where the files were removed sometime between Avast detecting them and actually scanning them, and a second quick scan usually solves the problem and the notification doesn't show up again.  However, this time I got the following notification and it doesn't seem to go away:

Error: The file cannot be accessed by the system (1920)

There are a whole bunch of these notifications, and I found that the all seem to be coming from a folder in C:\Windows\temp.  The folder name itself is just a guid and contains some folders and files within it.

I saw in some other threads that you guys said not to worry about this, but I'd like to do something so that this notification doesn't keep coming up every time I do a quick scan.  I worried about an infection hiding out in some folder or files that apparently Avast can't seem to get to.  Any help would be appreciated.

[jpChris]

Clean your Temp Files daily. See if that helps before a quick scan.

[Cokomon]

I just ran the Disk Cleanup, but that didn't clear the folder in question.  It is just in the temp folder and is, according to the modified date, over a month old, so I figure it probably is ok to just delete it.  The folders inside it seem to be some temp backup that windows made, as they are Program Files, ProgramData, Users, Windows, etc...

Not sure what this folder was for, but yeah, probably ok to clear it out so it stops interfering with Avast.

[jpChris]

Hi Cokomon,

Use CCleaner and\or ATF Cleaner to get all the temp files removed from everywhere.

[Cokomon]

I'll check it out, thanks for the help.

[jpChris]

Sure! Please post back and let us know it it helped.

[Cokomon]

Hmm, CCleaner found the folder initially but doesn't seem to have deleted it.  Avast still giving me the scan error and CCleaner doesn't seem to be finding the folder/files anymore.  Not sure what to do now.

[Cokomon]

These files seem to be owned by TrustedInstaller, which is why I can't seem to scan or delete them.  I'm wondering if this is leftover from my recent upgrade from Windows 8 to 8.1.  Although the date on the folder seems to be older.  The folder was modified back in August, but I upgrade last week.  Not sure why Avast never had trouble with this before.

[jpChris]

CCleaner empties the folders - not delete them. What version of Avast are you running?

Also, this article may help you -but I don't know?

http://helpdeskgeek.com/windows-7/windows-7-how-to-delete-files-protected-by-trustedinstaller/

[Cokomon]

Well yeah, I know it clears out the temp folder, not deleting the whole thing.  The problem was that the one thing I expected CCleaner to clean, it did not.  And I kind of figured changing ownership away from the TrustedInstaller would solve the issue, I was just double checking that this would be a good idea.  I'm not sure why ownership got changed in the first place.

[jpChris]

Did changing "ownership" solve the problem?