I can help you, but it’ll cost you
No, seriously
A while ago i downloaded SP2 and it completely screwed up my system, then when i tried to remove it, it removed associated files which forced me to reload Windows entirely, it was a pain to say the least.
As i found out, in order to install SP2 your system needs to be completely free of viruses, adware, spyware, etc, or it will screw up your system
These things didn’t show up on virus scans, so i had to go into my system32 and look for recently created .exe files, and remove them manually, they could be anywhere on your PC but usually i found them in the system32 folder
I hope this is not what happened to you, because it is a real pain and will take a while to fix, go to the majorgeeks.com forum and you will probably find some good info about this
If i were you i would try to remove the SP2, then clean my computer, then reinstall it, mind you, my opinion is just as good as the next guys, i am no expert in this field, just had a similar experience with SP2
Take care