[Skybird]

@Dandyman, the cause of such locked computers in principle is a virus infection of any kind. And so the argument is the same: when manually regaining access to the system and then using a system restore point, you are still left with the residual risk of still having that malware, traces of it, sleeping parts, on your HD. You can run a viruscleaner then, yes. And still never will know for sure that it did what it claims to have done (=cleaning the system). Ergo: format and kill it all.

Virsusscanner do not get called "Virus repair kits". Their job and that of Malware scanners is not to repair systems, although they offer such features, but to scan for and find infections that do not reveal themselves to the user (trojans grabbing off data, for example, bot net trojans, keyloggers)

So save your time. In the case here, wipe the HD immediately, don't take a break at trying to reactivate Windows surface first. What for? you will never have guarantee that you really killed that damn thing.

I even would format two or three times, with power interruptions between each turn. Not before then I would physically connect an external HD with an (old!) image.