Xdmemes

Hi, I recently installed a new seagate barracuda 1TB, after transferring the files from my old hdd to my new 1tb (copied I know I maybe had to use a cloning software). When I installed the new hdd in my computer my pc could not boot anymore. I'm almost 100% certain that my windows 10 is on my SSD. When I start up my pc it gives a black screen with the message that I need to insert boot media. I tried almost everything I think, I checked all the cables they were all connected tight. Also I tried to boot from a USB drive with the windows media creation tool and then selecting the repair my pc option but it said that there wasn't any problem (this while the hdd was connected and also tried with a disconnected hdd). Even without the media creation tool inserted into my computer the pc would not boot. Always the same message that I need to insert boot media. My pc is a bit outdated but still runs fine, it has a 550W PSU and the Motherboard is an asrock H61M-DGS with an intel i5 3450. 8 GB of ram and a 960 2GB Vram. Hope someone can help me out, Thanks Regards Mats