My computer one day suddenly stopped sending any signals to my display, so I just decided to take the chance to upgrade to my friend's old computer. Of course, I needed to reinstall windows cuz my friend's computer used a different motherboard, but I wanted to keep my files. I borrowed my friend's old hard drive and connected my own hard drive to my friend's computer in order to transfer the files i wanted. After I transferred the files and installed windows on my hard drive, I disconnected my friend's hard drive as it was no longer needed. But after restarting the computer, it wouldn't boot from my hard drive. It would only allow me to boot from it if both mine and my friend's hard drive were connected to it at the same time. The Bios Settings still recognizes the hard drive, but for some reason it has somehow become reliant on my friend's hard drive to boot. I want to make the computer boot from my hard drive without relying on any other hard drive. Any help would be appreciated.