windows update causes an error popup w/ wininet.dll

I haven't had this error before, I'm on XP SP2 and when I attempt to use
windows update, everything goes fine until it starts looking for updates.
Then I receive an "Error Signature" with the following info:
AppName: iexplore.exe AppVer: 6.0.2900.2180 ModName: wininet.dll
ModVer 6.0.2900.2518 Offset: 00004621

I've tried turning off my software firewall (Norton) as well as my antivirus
to no avail. I've also attempted to load via safe mode with networking with
the same error. I added windowsupdate as a trusted site hoping that might
help but it didn't. At this point I'm not sure if auto-updates will work
either. I had early on also attempted to clear my cache and history and any
temp files, I realized I'm getting the same error message above when I choose
Tools > Internet Options > General > under Temp Internet Files > Delete Files
> check Delete all offline content. The same wininet.dll message .. I can't
think of any software or changes to my system that could've started this
error? I've done spyware scans and virus scans and came up with nothing ...
can anyone help?

Thank you!