I need help with a virus (not the computer I'm currently on)

[tacticslion]

To explain: several months back, I was doing several things online simultaneously. Somewhere, somehow, on one of the sites I was on (I'm unsure if it was this one, Spoony's, or another), I accidentally clicked on an add that I couldn't see yet (it was one of those moments where the page isn't fully loaded, you click on a blank spot, but NOPE! There's an ad there you couldn't see, and now it'll load and take forever!). Turns out it was a porno site, and the thing wouldn't go away. Whenever I tried exiting, it always asked if I was "sure" I wanted to navigate away, please choose yes/no - since I didn't know or trust the site (and the requirement of specific permission to go away seemed kind of dodgy to me), I was leery of clicking anything, however when I closed that option box, the page remained. I tried shutting all of it down, but when I opened my browser again, it reloaded my previously interrupted browsing windows, including that one. Eventually, I just gave up and and clicked "yes" that I wanted to navigate away and it let me and that seemed to be that.

Later that day, however, I started to recieve notifications that my computer was under attack. I've got Norton, and it's consistantly up to date, so I felt reasonably (though not terribly) secure, but that was still disturbing (I'd wondered if, by answering, I'd given away my IP address or something - I honestly don't know). Norton was pretty good about finding and removing things, but recently the attacks have increased in frequency. Apparently recently, somehow my internet connection loaded but Norton didn't. I didn't discover this until later on, and turned Norton on, but was too late. I was instantly inundated with pop-up windows including "porno.com", "porno.org", "viagra.com", and "adult.com". These won't stop coming. Further, I'm being 'warned' that my computer is under attack and it is carefully explained that I should activate my antivirus (complete with near-Microsoft imagery and stuff!). It's all very convincing-looking, except for the fact that I have an antivirus, and that isn't it, while it's trying to get me to believe that it's scanned and discovered threats. Also, with careful visual inspection, you can see inconsistancies in the artwork of the dialogue boxes compared to actual Microsoft stuff. Finally, worst of all, whenever I try to anything - that is anything at all - I recieve a notification that that program "is infected and cannot be opened", along with a coersion to activate my antivirus program (which I'm watching scan for and locate viruses). The only program that I've tried that seems immune to this is Norton. Even Ctrl+ALT+DEL doesn't work - it claims the task manager ("tskmngr.exe") is infected and won't open. I have no idea what to do. Currently, my computer is disconnected from the internet (though the pop-ups are still coming, so I'm presuming it was an actual downloaded virus instead of an attack on my IP address?), and I've got Norton doing a full system scan. Oh, and one more thing: my computer's been shutting down seemingly at random recently (I believe this to be overheating instead of specific virus/worm activity), so Norton doesn't really have much time to do a full system scan.

I hate porn with a passion, and I'm incredibly frusterated that I've apparently recieved a virus from a site I never wanted to go to and of a kind I try to avoid. The computer I've got now is... okay, but it's old, slow, can't handle much (this forum causes a bit of a delay) and the keyboard is slightly glitchy (it's an old laptop with a touch-pad mouse, causing all sorts of fun glitches and typos) and most of my stuff and games are on the other one.

tl;dr: lousy virus infected my computer. I've disconnected from the internet, and Norton's doing the best it can, but because my comp's recently developed an over-heating problem, Norton usually gets interrupted before it can do anything. Help?

P.S. anyone here work for Dell? 'Cause that's what it is.
P.P.S. no, I can't conclusively prove it was that one site - I don't even know which one it was. The timing is too coincidental to ignore, however.