how 2 repair windows?

[Gamer]

I have gotten to the screen which asks if I want to reformat or repair. I press R to reapir then select the drive but then it asks for admin pass my dad can't remember having one. If i just hit enter it goes to C:/windows and then has the blinking type icon or whatever it is called. does this mean there wasn't a pass, and if so what do i do from there?

[Gamer]

O and my OS is xp prof

[HAL9000]

You are trying to repair from a command console.. you want to select install, then on the next menu you will get an option for a repair installation, no passwords required.

[Gamer]

o ok thanx