.. ok I was furiously DLing some porn the other night

...when I definitely got some horrible virus, a trojan I think. 400 pop-ups, 200 errors, 100 deleted things-i-hope-arent-important, 40 different ad-aware and spyware tests and scans, 20 anti-virus scans and 10 restarts later I think we're all good now.
Should I seek professional expertise or who thinks i can get away without?
Dammit that shit sucked... what the hell is a trojan anyway?