Can’t Activate Windows Ten

A few days ago I upgraded my Windows 7 to Windows 10 using the direct to pc upgrade. I did this by downloading from the net when my Win 7 Pro 64 was installed.

I then formatted the HD and did a Clean Install from the .iso file but it wont let me Activate Windows Ten. It says the CODE is WRONG.

What can i do to Activate Win Ten? It now comes up on the Desktop saying this needs to be done.

Thanks