Shane -- you uninstalled SP2/ did all the 'cleanout' steps/ then did you
reinstall from a clean-boot state when you reinstalled SP2??
http://support.microsoft.com/kb/310353/
if you did not --of course nothing changed-- you did everything but the
most important part.
As I stated in my previous post-- this is a major OS revision-- not a normal 'windows update'-- if you are having install issues -- you usually need to change something DURING install that could be interfering with proper install. Namely THIRD-PARTY Software like your antivirus/firewall. ESPECIALLY if you run Norton products. I have had more difficulties due to Norton during installs than any other single program. That alone could be the problem. I am not--at this point -- absolutely certain, but if I was a betting-man-- I'd be betting on Norton as the SOURCE of this. Norton gets into corners of your computer that are unbelievable ( ask anyone who has tried to uninstall it -- took me three weeks to root it all out !) Just when you think it's all gone/ shut down forever-- you go to start some program and it crashes due to some hidden Norton fragment in a dark corner of your registry.
Tricky issues require following instructions completely.
I mean no offense