I've recently taken over managing a number of Windows 7 workstations on a 2008 AD. One workstation displays only two (domain) user accounts as options for logging in. Local admin is not displayed. Both of the displayed domain accounts have been deleted. So, a disgruntled user has managed to lock out everyone. All Safe Mode options wind up at the same place. I would rather understand what's going on than simply rebuild it. No other admins around me has seen this.