mchain
9
Similar issue later determined to be a false postitive: http://forum.avast.com/index.php?topic=139878.0
Clean, quarantine, or delete? http://antivirus.about.com/b/2007/03/11/clean-quarantine-or-delete.htm
To OP, please be gentle here, 'twas done in panic mode, so…
Another file query site: http://www.bleepingcomputer.com/startups/IDriverT.exe-17105.html
Hope this answers your question. You could try running sfc /scannow in cmd and see if windows recovers that file for you after the scan is done.