Can't login to cpanel x3

[helpfro3]

Hello all
i'm new to all this
Just recently had to rebuild pc & lost all my login details.
I have found the standard login page
When i login i get this error

Before my pc rebuild i used to login from x3 theme cpanel.

I'm kind of lost with this
Why cant there be just one login page !!

Any help will be appreciated
thank you