Cannot clean or repair virus

I am using Avast 4.6 Home edition (thanks for providing it for free). Did a full system scan. It found a few viruses. But it doesn’t provide an option for cleaning or repairing the infected files, only delete or move. Where do I find the repair/clean option, if there is any?

Files may be not repairable. avast uses VRDB to repair certain files, but if it is not generated, the repair option won’t be available. also. vrdb should be generated only at clean PC.

What was the virus name, what was the filename, where was it found
example (C:\windows\system32\infected-filename.xxx)?

Only executable files (.exe, .com) are repairable. VRDB will store the info for the last three versions of the executables in order to repair. So, if you let the default period of 21 days of VRDB generation, you could wait until (21 * 3 - 1 ) 62 days to repair the file. It won’t be probable that you need this file (clean one) after this period. So, repair is available when is possible. You can’t bring a repair buttom back is it is not possible.

The two first of them should be Automatic loaded and the two last Manually loaded.

It is an executable file (not in Windows dir)
VRDB was generated on 26 Dec 2005
Virus was found on 7 Jan 2006, name “Win32:Trojano-1403 [Trj]”

If I understand correctly, Avast “cleans” an infected file by restoring a kind of backup? It can’t clean an infected file that I newly downloaded somewhere from the Internet?

Trojans generally can’t be repaired (either by the VRDB or avast virus cleaner), because the entire content of the file is malware, so it is either move to chest or delete, move to the chest being the best option (first do no harm). When a file is in the chest it can’t do any harm and you can investigate the infected warning.

The VRDB only protects certain files, .exe, dll and other system files, it doesn’t protect data files or all files, it is not a back-up program, so there are going to be many occasions where repair won’t be an option.
Only true virus infection can be repaired, e.g. when a virus infects a file it adds a small part to it, provided that file is one that avast’s VRDB would monitor and you have run the VRDB, then it may be possible to repair the file to its uninfected state.
However, for the most part so called viruses, trojans (adware/spyware/malware, etc.) can’t be repaired because the complete content of the file is malicious.