New build problem installing windows7

I just turned on an almost new build pc to install windows7. The entire pc is a new build except the hard drive that has a good copy of xp installed. Im trying to install a new copy of windows 7 on the hard drive. So I turned the pc on and go intoO the bios to set the DVD to boot first. So windows starts to install and the window is loading bar comes uP. after the bar gets over half full, the screen drops and there is a line of h's on the left side of the screen and the installation freezes. Anyone know what is going on? Thanx