corrupted user file. I had to dig into a User Profiles folder and change the name of a file. This just got it working. All his files were backed up, which is a good thing because now they're gone. Still it's not working properly, the Start menu isn't displaying like it used to. The Mail app isn't launching, his bookmarks are all gone.
The next time he starts the pc I think there's a good chance it will happen again.