I think the three files Tech mentioned may well be the protected copies of system files which avast! stores in the chest.
p2psetup[1].exe is a P2P adware file. Some P2P networks come bundled with adware/spyware and are best avoided.
See here:
http://www.spybot.info/en/articles/infected_and_clean.html
The files detected seem to be in temp files and System Restore files.
To delete temp files, try using CleanUp:
http://www.stevengould.org/software/cleanup/
I also suggest you run Spybot and also Ad-Aware and a-Squared free to check for traces of adware:
http://www.download.com/3000-2144-10045910.html
http://www.emsisoft.com/en/software/free/
To remove files in System Restore, you will need to temporarily disable System Restore and then turn it back on again, as described here:
http://www.pchell.com/virus/systemrestore.shtml
and here:
http://antivirus.about.com/od/windowsbasics/a/systemrestore.htm