Seriously, how on earth can anyone help you with information like that?
Tell us more – starting with
The specs of the PC you are upgrading
The current windows version (not just “7 or 8”
How you are upgrading (online or from media)
What error you are getting
And finally, what have you already tried to solve it?
That way someone may be able to start helping you (probably by asking a lot more questions at first) or may be able to point you at something that can help more.