I've never used AVG and I gave up on AdAware and Windows Defender some time ago because they didn't seem to do very much (and some things I've seen online suggested they weren't very good, but I have no 'proof' of that).
From what you posted it appears that your 'problems' are either in temp files or where Housecall stores its quarantined items. Clearing your temp files by using Windows Disk cleanup may be all you need to get rid of the things stored there, and I assume it must be possible to access Housecall's quarantine folder and delete the contents, but I don't know how because I have never used it. In any event, quarantined items should not be able to do any harm so I suppose they could be left where they are.
You could get a second opinion by running another online scan, the Eset Online scan for example, and see what it finds;
http://www.eset.eu/eset-online-scanner If you do decide to try it, be sure to read all the instructions first.
It wouldn't be unusual for something obtained via P2P to be infected or for some 'security' programs to 'miss' things others don't. There is also the possibility that some programs are producing 'false positives', so that what they 'find' is not malicious at all.