Situation: You just cloned your Windows 8.1 Windows on a new (SSD) disk with Acronis, Synology Active Backup or Aomei Backupper ; everything is going fine , but you cannot upgrade the Windows to 10 because you cannot activate it, a list of error will do the messages …

You should do the following steps

  1. Run an elevated CMD prompt , WIN+X > Command line with Admin
  2. RUN (copy paste the following)

slmgr /upk
slmgr.vbs /cpky
slmgr /ckms
slmgr.vbs /ckms
slmgr /skms localhost

3. Download Recover lost Windows product key, launch it and recover the hidden key

4. In the CMD already opened window RUN

slmgr /ipk KEY (you just obtained it at step 3)
slmgr /skms
slmgr /ato

5. Download Windows Assistant and run it

When everything is done don’t forget
* change the Windows licence with a new one if you will use both computers
* change the name of the computer if you will use both computers
* duplicate user in domain if you use both computers on same network

BONUS, a funny message (for me is a first time i see it)