I think idea one, is put Norton back on it for now. Idea two, is put Norton back on it for now. Idea three, is put Norton back on it for now.
I haven't bumped into Avast or whatever - but Imscan looks suspiciously like Instant Messenger Scan, which means that the rest of the machine could be, or is, open to the predations of Vinnie the Virus writer and his many mates.
Go back now to para one and we can think of something from there, but for Gawds sake, get an Anti virus package on there, because everything else will very soon become a tiny problem in comparison
Yours from a distance,
Conan