Screen goes black on last step of Win7 installation

Created Windows partition via Mac side just fine, then inserted Win7 installation disc, restarts and goes most of the installation process, but then goes black.

Once we start it up again, it gives us the option of starting up in a few versions of "safe mode", or to "run windows normally". When we choose any of the safe modes, it says that we can't finish the installation in a safe mode. When we choose to run windows normally, the screen just goes black again (indefinitely, though the computer still seems to be on).

If anyone has fixed/understood this problem, please HELP!! Thanks!!!