install worked on my mac laptop, but not on my imac PLEASE HELP

I just installed Windows 7 on my mac laptop and when i try to do the SAME EXACT thing on my imac it turns black and says 1. 2. press boot options and it wont work.

can somebody please tell me what is going on? They are on the exact same OS, it makes no since why 1 would work and the other not?

this is what I get -

1.

2.

BOOT SET UP

Did you use Boot Camp to install it like this tutorial?:

http://www.simplehelp.net/2009/01/15...e-walkthrough/