Blank White Screen on Startup

[ghking]

hello
i was on my xp partition and i restarterd my mac to go back into osx. When i did, it made the chiming noise but then hangs on a blank white screen. I have left it there for almost 3 hours and it still hasnt started up. HELP PLEASEE

 

[Sky Blue]

Can you boot into single user mode? try doing a fsck -fy

 

[ghking]

ahh its doing it again
how do i do those things

 

[ghking]

it only seems to be doing it now when i start up holding down option trying to get to the OS selection. I havent been able to get to windows.