When you boot a computer and all you see is a black or blank screen with a blinking cursor (it may look like an underscore), it means the BIOS or UEFI is attempting to boot from a source other than ...
Ensure your PC boots safely before Secure Boot changes.
Its probably just the boot order. Go into the BIOS and make sure its trying to boot from the correct hard drive first. If you aren't sure what drive you are supposed to boot from, just switch whatever ...