Please don't delete any files or registry entries.
This is simply a bug in housecall.
If none of the other antivirus programs detects it, then you are not infected.
Housecall pops up the same message to me. But it does that way before it started scanning. And at the and of the scan it doesn't detect any infected files. Normally, it displays a list of infected files and suggestion on how to deal with them.