This has happened to several computers on my work domain. The computer will work fine one day and the next day the user will come in and the computer says Windows is not active and everything is gone. It looks like the computer has just had windows installed on it. It is no longer joined to the domain and none of the user accounts are active. When you browse the hard drive all of the user profiles are still there and all of the programs are still there but they don't work. It looks like a system restore happened but the computer did it on its own.
Any sys admins seen something like this happen?
Any sys admins seen something like this happen?