This add virus, which manifests as a banner with, for example "Play now", "Download Now", "Win an iPhone" bla bla bla, has been spreading on my browser (yes, I tried, IT, and Firefox) lik a wildfire.

I got it by being very stupid...stupid...I saw a link on Facebook, pressed it and it wanted me to download a file...and so I did, damnit, that wasn't smart. So, now wherever I am I see these adds.

I tried reinstalling Chrome. Tried a different browser. Did a deep-scan with Ad-Aware and VIPRE.

I don't know what to do. I am desperate.
Please, any, ANY help is much appreciated. If you need any print screen on what it looks like, I'd be happy to oblige.