sounds like you'll need to do a fresh install.

Personally I think aol is the worst possible isp one could pick.  Go for something that doesn't require a giant, messy, controlling client and something cheap.  That said, did IE work before aol got installed?  Try connecting to the net (get a friend to give you another ISP number worst case) and using it after the clean install.  If it works, which it will, and then doesn't work post-aol, blame the aol people.  If you can get a discounted version of XP you could also try that (as it wouldn't be related to dell in any way), but I don't think you should need to do that.

I used aol from versions 1.2 to 5; run away while you can ;p  Actually, on that note, if you want aol for free, just try to cancel, you'll get at least 3 free months to reconsider (esp if it's because you're upset at them).

Oh, final note.  Have you tried an alternate browser?  Give netscape or mozilla a shot once aol is up to make sure it's not a connectivity issue.  I assume aol still supports netscape anyway (although you used to have to download a couple of special files for it?)