This morning I read about a crash issue with Service Pack 1 for Windows 7 on machines that came with the preinstalled OEM copy of Windows 7. Nick Whittome posted a description and various workarounds on his Facebook page.
EDIT: there were some issues with the Facebook link so you can go to a post on TechNet instead.
Technorati Tags: Windows 7,Windows Updates
Looks like that Facebook link is already dead
I modified the post to send people to TechNet instead.