If it boots okay in Safe Mode, then do that an enter System Restore and take it back to just before the updates. Hopefully that will fix it, then you can run the updates again, but perhaps just a few at a time.
I think I know what happened. I used a program called Your Uninstaller! 7 to remove unwanted and orphaned files from my hard drive and I remember seeing some files called *userinet* that it deleted.