bootmgr is missing when trying to boot from a SATA HDD

So hello guys, I had this other computer that had a SATA HDD with windows 10 on it. Then I bought a computer with an nvme m.2 and installed windows on that, now I can't boot into my previous windows 10 that is on the SATA HDD. At first i had the problem "insert boot media disk", fixed that but then I got into bootmgr is missing and I can't get past that with bootrec /fixboot because i get access is denied and to fix that I found some commands that i think will delete my partition, which i don't want.

Help.

Bancai said:

So hello guys, I had this other computer that had a SATA HDD with windows 10 on it. Then I bought a computer with an nvme m.2 and installed windows on that, now I can't boot into my previous windows 10 that is on the SATA HDD. At first i had the problem "insert boot media disk", fixed that but then I got into bootmgr is missing and I can't get past that with bootrec /fixboot because i get access is denied and to fix that I found some commands that i think will delete my partition, which i don't want.

Help.

Solved it:

1. disconnected the m.2 nvme ssd from the motherboard
2. Went into the recovery command prompt
3. Typed diskpart
4. Typed bootrec /fixmbr , bootrec /fixboot , bootrec /scanos , bootrec /rebuildbcd . Last didn't work so onto number 5
5. Type exit
6. Type bcdboot.exe c:\windows /s C:
7. Restart computer and waited for windows to do its thing - took around 2 min and then it restarted by itself followed by some 5 more mintues of waiting for windows to prepare windows files time in which i thought i ****ed up and my windows partition or at least the main profile would be erased...but no, i was greeted with my original account so all good.