Right, well as you may have guessed by my absence, I've bin and gorn and dunnit!
Didn't go quite as expected. First of all I just did an upgrade (install on top) of XP, but that didn't really sort things out, and then I couldn't get the Internet Connection Wizard to work, and the Favorites thing was still wrong.
So I went for the full new installation. Put CD in, and did all the right things (well, all that it would allow me to do), but it wouldn't let me delete C drive, before re-installing. Went ahead and installed over the top, and it said it was deleting everything, but when it was all done, I found that there was still a lot of stuff left on C drive from the original installation.
So I did it again.
And it's still the same.
Everything works OK now, except for some strange messages from Norton about possible problems with the integrity of the protection. It said, it couldn't be certain, whatever that's supposed to mean. I did a virus scan, which was clear, then I ran a trojan scan, which was also clear, so if there's still something in there, I'm buggered if I know where it is.
I still have lots of stuff from the old installation, and I'm not sure whether to delete it, or if the new installation may have used some of it already (Program Files and stuff), so I'm going to leave it for now, and see how it goes.
Still got loads of software to re-install, but that will be a job for tomorrow. At least I have my AV and Firewall up and running, and can get online, so I'll sleep sound tonight!
Night folks, and thanks for all the help!