hi guys,

Quick question. I've got to go see a customer tomorrow who had a lenovo laptop running win10.

Sadly they took it to PC world and the gimps there re-formatted it back to 8.1 that was stored in the recovery drive and handed it back saying it was fixed, despite wiping everything from the drive apparently.

What the simplest way to get it back to 10?

Would the microsoft account, when signed in, flag that it needs the windows 10 upgrade and do it automatically?
Do i need to call microsoft and explain and they should give me the windows 10 key?
Last resort wind back the clock and put 10 on it?

I'd prefer to do it legitimately .

thanks
MML