I'm not an expert but I've used NOrton products for a long time. You should mention WHICH Norton product you installed: Several of them contain the anti-virus application. NIS, AV, 360, etc.. That way you might find someone with the exact same problem on the exact same program.
From your description, it sounds like the virus/trojan/worm/whatever infection succeeded, especially if Norton wasn't allowed to act on it right away. They symptoms you describe aren't unusual and are typical of a malware infestation.
Since you have no firewall, turn on the XP firewall in the meantime. If you get desparate, you could also install a free AV program called AVG. Go to http://www.avg.com/us-en/homepage for the free version .
You could first try going back one or two or even three more Restore Points; there was your son's use to get past, then your wife's, and then any automatically created Restore Points, so you need to choose a date/time that was definitely before those points.
That will have the side effect of cancelling the Norton install, along with anything installed after the date/time of the Restore point, but it may well get your PC into a state that will let you re-install Norton, thereby satisfying the Security Center's messages.
So, back up furhter in time and try reinstalling Norton, whichever program it is. If for some reason you've deleted or lost the installation files you have before, it's still in time to go to the site and re-download the whole Norton program over again. I forget whether it's 15, 30 or 60 days they let you redownload, but you can do so.
If the restore points don't help, then since you can get the computer to at least boot now, and if you managed to get internet access back, you can go to Symantec/Norton and run their Online Virus Scan and Cleanup tool.
If you can't do so at first, then try it agan but this time from Safe Mode.
At this point ylu will have reached the point of diminshing returns and the easiest and fastest way to get it all fixed is to do a clean reinstall of the operating system, something else you didn't mention. Depending on the manufacturer, model and brand of your computer, you will either have on-disk recovery software or separate discs cotaining the operating system and utilities & drivers. Use whichever method you're comfortable with if you have both.
After you've tried everything you can, from me and others too, come back and let us know how it's going or just ask for clarification of any issues you don't understand . One thing about computers, there aare ALWAYS a dozen ways to do almost anything needing to be done<G>.
Looking forward to your reply,
Twayne
