不是高手, 知道一些而已 : )

A user profile is a file that kept in the Registry that contains a user's desktop settings and personal setup preferences to be retained from session to session.

If a user profile got corrupted then you might experience the error that you had before.

It could be a virus or spyware that caused a corrupted user profile.

If you want to get your old files back then you can try tools such as EasyRecovery since you already restored your PC.

EasyRecovery's website:
http://www.ontrack.com/