BleepingComputer.com: Vista 32bit hangs at startup

I have a Toshiba Satellite that came with Vista Home pre-installed. I upgraded to Ultimate SP1 several months ago and everything has been fine. Apparently, one of the recent updates has corrupted something and now it won't boot up normally. It hangs at the progress bar and refuses to finish booting. I can boot into safe mode with no problem. I've tried nearly all of the suggested remedies from numerous sites (renaming files, Last Known Good, System Recovery, memory checkups, disk checkups, etc.) with no success. I just installed SP2 and it is running the installation stage 3, but I am not too optimistic. All the hardware seems to check out OK and I really don't want to reload. Any ideas?