the path of the file system which cannot be scaned is m: C:\Program Files\Alwil Software\Avast4;;{E211B736-43FD-11D1-9EFB-0000F8757FCD}devid:{6BDD1FC6-810F-11D0-BEC7-08002BE2092F}\0000:
it cannot be seen,but can be scanned this way :
the filesystem belongs to Avast itself, if you want to scan it successfully.
right click on the icone of Avast, click “Stop On-Access Protection”.
Open “Desktop” in the address bar, Copy and Paste this : C:\Program Files\Alwil Software then press Ok
you’ll find a file named " Avast4" right click on it then “scan Avast” and try to scan it.
and see if you’ll have the same error.