Blinking underscore when installing windows

[bartekmordka]

I just completed buying all the components for my fun pc build and putting it together. When all was set and I checked if the temp and all is good in bios, it was time to install windows.Used my windows 7 x 64 ultimate that is on a usb and when I tried to boot from the usb it went straight to a black screen with a blinking _. The same thing when I tried booting from the hard drive. Windows copy and bootable USB working ( Checked on another pc) Do you have any suggestions ?
Spec Gtx 750 ti , Xeon e5450 , be quiet l7 4300 ,8 GB ram mb: asrock g41m vs3

 

[Wolfshadw]

Did you change the Boot Priority in BIOS to set USB first?

-Wolf sends

 

[bartekmordka]

Did you change the Boot Priority in BIOS to set USB first?

-Wolf sends

Yes I did , when I boot from a hard drive same thing happens. Blinking underscore