Ok Julie,
It looks like you can get here and post ok. Have you done the TrendMicro scan I posted above?
Since I can't see your desktop from here, could it be that the pop-up that says Unlown Error, please reboot is actually a malware program? What happens if you don't reboot?
Other things that have helped me in the past:
1- Delete all Temporary Internet Files [Tools] [Internet Options] [Delete under Temporary Internet files] (I also delete offline content when prompted).
2- Browse to your Windows Temp file and delete everything that will delete.
3-Reboot and see what comes back. In REGEDIT drill down to HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\Curr entVersion\Run and see if there is something loading that shouldn't?
Then if this doesn't work, delete your cookies or at least remove ones you don't recognize.
Good Luck