W10 Not booting at all

[DegoDani]

Quick summary:
-Every time I start my computer it turns on for a few seconds, turns off, then it starts properly.

• It always threw me into the BIOS, where I had to ”boot override” to boot w10
• W10 is on my SSD, but I have to boot override my HDD to start (No clue why, would like to know)
• The real problem is here: Now I’ve gotten a new harddrive, and I can no longer boot my computer at all.

Help desperately needed. I know, vague descriptions, but maybe someone else has solved a similar issue and knows what I’m talking about.

Thanks.

EDIT:
Plugged the old hard drive in, booted w10. I went to disc management and saw that the old hard drive contains some ”system reserved” space. How has this happened, when I installed w10 on the SSD? Is there a simple way to get this to the SSD?

[jmarket]

EDIT:
Plugged the old hard drive in, booted w10. I went to disc management and saw that the old hard drive contains some ”system reserved” space. How has this happened, when I installed w10 on the SSD? Is there a simple way to get this to the SSD?

System reserved is a normal function and inclusion of a Windows 10 install.
Yes you can copy your mechanical hard drive to your SSD but chances are youll clone your problems as well. Free software like Macrium reflect or Aomei Backupper will clone your OS and data to your SSD.

[DegoDani]

With windirstat I saw a 16GB file in the old hard drive, as well as over 170GB ”unknown” files (backups maybe?).
Just adding stuff I’m observing.