When I boot my pc it loads past bios to a blank screen with a white blinking dash in the upper left corner of the screen....reboot same thing......reboot.....and it works, then after shut down it the same sequence any idea why?

Hello it sounds like your computer is trying to read the boot order.Go into BIOS and check what is there?Set first boot to HDD then CD/DVD rom etc.

Or loading devices and drivers.Please check Bios setup is correct.