[Avast Detected When I've Never Installed It]

When you bought your computer, did you buy it absolutely brand new?  Are you the only owner of that computer ever?  Anyone else use that computer now?

 

If you bought that computer second hand, a previous owner could have installed various anti-viruses when they had it.  I've had various 2nd and 3rd hand computers and when I check deep into files, folders and registry entries, I find remnants of one or more anti-viruses still roaming around aside of the anti-virus that's currently installed.

I actually bought the computer parts new and put it together myself. It's my private computer (that's password locked) in my house, and the other person living here has her own computer.

[Avast Detected When I've Never Installed It]

Ok, I've been reading a lot of people talking about V5.00.5050 picking up Avast 6 and 8 because of remnants left over. However, mine's picking it up after I've never even installed an Avast product on this computer before. Needless to say, this both worries and perplexes me, and I'm thinking a dupe software might have installed registry keys there without my permission.

Any ideas?