Please provide some more detail on this problem you are experiencing.
1
What remote worker tried to repair your system, was that some Microsoft Support person, and if so, how was contact made with them.
2
What problem are you experiencing with your PC now, will the PC not start up, and if so, when you start your PC, what is the exact sequence you see, do you see the PC manufacturers logo screen, then do you see the spinning dots to indicate Windows is trying to start, and at what part of the process does that fail and what error do you see.