My pc won't even turn on now after upgrade to 10 from 8.1
Hello Phil and welcome to the forum.
Sorry to hear about your problem.
"My pc won't even turn on" does not provide a whole lot of information.
What kind of PC is it?
Manufactuer Name, Model Name, Model Number (complete number)?
Will it POST, do you see the mfg's splash screen? Can you enter the BIOS? Are you getting any error messages. Does it just set there like it is not getting power? Any lights flashing, any beeps beeping?