virus or spyware help needed.

I formated last week and I just finally manage to get my windows back the way I like it to already notice that I probably have a spyware or virus that is really annoying.

Every time I do a search in the google bar search in firefox and i click on a link from the list that google found for me, there's something that always redirect me to some other publicity website that had nothing to do with the link I clicked.

for example: I searched "deviantart" in google bar, click on the first link that was "www.deviantart.com" and got this

http://67.29.139.253/jump2/?affiliate=and1&subid=2363&terms=deviantart

like so you see something redirected me where I really didn't want to go...

I tired downloading spybot, did a scan and it didn't help, I use avg as an antivirus and again it didn't find anything about this...

Anyone know what could cause this? and how to get rid of it?

I just don't want to reformat again just for this...only if it's the only solution.

Jam it back in, in the dark.