Idiotically impractical software
I gave it a whirl -- I freelance with banks using Windows machines, so it would be embarrassing to be the source of a virus/trojan or other nasty.
It took about 60 hours to trawl my hard drive and back ups and it found about 30 instances of one very old Windows trojan and two of another. It said it wasn't able to clean these automatically so I should do it manually.
But the really stupid thing was that the window that listed the paths of the files wasn't big enough so they were presented in truncated form (they were well buried in backups so had very long paths). Nothing I tried would make the software cough up the full address and let me actually find the damned things.
Perhaps I was being dim, but there is no way that I could act on the program's recommendation, so they're still sitting there. I think they're effectively harmless, being so old, but the same problem would presumably apply if they were the latest cunning and dastardly attack.
Complete waste of time simply because of poor UI design.