I have a question regarding the basic way that Avast handles a detected virus or trojan. Some of the infected files are in the windows system folder and appear to be needed for Windows to function properly. When I move them to the chest because of being infected, does Avast clean the file IF it is a windows function file or move the entire file to the chest so that the functionality of Windows could be affected? ???
Repair is the only method of cleaning, this option is only offered if it is theoretically possible. Moving to the chest does just that no cleaning just moving it to the chest so it can’t harm the system.
It is a common tactic for malware to install itself in the system folders to confuse/deceive you into not removing it thinking if it is in the system folders it is essential. They are often named to confuse by being misspelt or very close to a windows file.
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.
Welcome to the forums, LdyTorie ! 
Please come back often, learn more, and maybe help others.
Thank you so much for your speedy clarification, DavidR! Now I feel comfortable moving the files to the chest for a week or so if the “repair” option isn’t available. And thanks CharlieO for the welcome to the forum!
Trisha (LdyTorie)
Your welcome.
There is no rush to delete anything from the chest, they can’t do any harm there. Anything that you send to the chest you should leave there for at least a week or two. If after that time you have suffered no adverse effects from moving these to the chest, scan them again (inside the chest) and if they are still detected as viruses, delete them.
Welcome to the forums and avast!-
Hi, Very new user. And not a tech person at all. I have removed several viruses (all exe sysvolumerestore but different numbers and all end in trojan gen) All the same size. Seem to be connected to leaving machine on. I’ve been trying to get how to deal with them. After they have been there for several weeks, I can scan and then just delete? From what I understand, the system functions are backed up in the chest? So, if something is then missing from a system function will it be restored automatically? The only thing I notice happening is that I keep having to reboot to get back on net if I have left machine on and walked away. Under these circumstances also get virus as I said already. I also have a couple of malwares, but they seem to be related to the fact that I am not using administrator but another log in because this computer was given to me used. It has Windows xp.
Please help. I am a social justice nerd, not a techie. I already have too much to do. Thank you.
If you find a virus keeps coming back after you delete it, it’s most probably infected the System Restore folder, the best way to solve this is to disable System Restore, reboot your machine and then enable it again. After all, run a full avast! scanning. System Restore cannot be disabled on Windows 9x and it’s not available in Windows 2k.
Enable/Disable System restore on Windows ME: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q264887
Enable/Disable System restore on Windows XP: http://support.microsoft.com/default.aspx?scid=kb;[LN];310405
Do you mean into Chest (Quarentine)? Yes, you can delete them after this period.
Right again.
No, just the three files could be restored IF they were virus infected.
Can you schedule a boot-time scanning?
Start avast! > Right click the skin > Schedule a boot-time scanning.
Select for scanning archives.
Boot.
Welcome to avast forums 8)