Webroot isn't picking up a virus/malware called smiley face matrix, flashes on and off, with images,

I've completely cleaned out mozilla firefox from my computer & registry, and still it came back.
Been on IE & it doesn't show up on there. It doesn't stop my computer from working at all,
but it's annoying, make me feel "infected"!!!
 
Can anyone help? Tried various anti-virus scanners, malware scanners & spyware scanners, they find
nothing. Also have tried registery recycler.
Used CC cleaner, looked through the register myself & nothing.
Cleaned out all old adobe's, java's etc
 
May have happened when I plugged into power as my battery was getting low???
 
Any ideas as to what to do.
 
Thanks
Helen Linklater