hanging half way through boot up after sp2 install

[willthepirate]

decided to be a good boy and install sp2 on my main box and...

when its on the screen that says "windows xp", and has the scrolling blue bars it reads from the drive a little bit, then just stops and hangs??

any ideas

need some help

 

[willthepirate]

no dice

ill just reinstall if theres no easy solution