Infected component.old. Can I delete?

I did a routine scan, uneventful and found that a trojan had snuck into C:\Windows\System32\Config\Regback\Components.old. I wanted to move the file to Avast’s virus chest but despite making the chest capacity unlimited and increasing the send file size to double componets file size I can’t put it in the chest so my question is can I delete it? Or will that mess up my system. So far it hasn’t done anything but I want to get rid of it to keep my system safe. It was identified as Win32: Vidlo-AH.

Edit: I restarted my PC as Avast sucked up alot of memory during the night as I left it running to do it’s thing. I came back and rescanned the supposedly infected file and it’s not giving me a virus alert anymore. Whats up with that?

Which is the size of the file?
The extension (.old) seems to make this file ok to be deleted.

Could it be a false positive… strange…

23,004 KB to be precise.

So, it’s not a reason to not being moved to Chest.
Are you sure the message wasn’t that the file was being used (access denied)? ???

Yep, I’m sure. And the hard drive it’s on has around 30 GB free, and the virus chest was set to unlimited capacity and the send file size to around 50,000 KB. I just tried scanning it now it still gives me no warning and I reboot the PC myself 2-3 times since this morning when this problem first appear (I did so for various reasons) and none of my other scanners (SuperAntiSpyware, Spybot S&D, Spyware Doctor) detected it. So what I plan to do is another through scan of the entire hard drive tonight and see if that file shows up again in the next scan.

Seems you’re clean.
A further check could be done with MBAM or DrWeb CureIT!.