New computer won't boot from the old drive

Factual Questions
1

It sees the drive, just not as a boot drive.
One option may be to get an M.2 drive and make that the boot drive. I was planning on doing that eventually. The questions are

  1. If I do that is there any reason I couldn’t access the old hard drive for the data?
  2. If I boot off of the M.2 and assuming the old disk is recognized, can I run apps off of the old drive?
  3. Any tricks to get the computer to recognize the old drive as a boot drive?
2

Typically, you should be able to go into the BIOS settings and designate the boot drive.

If it is a specific OS question you should please provide more details (Mac, BSD, Windows, Linux…) If your bootloader or other boot component is looking for the drive via a device name that has changed you may need to configure the bootloader again to account for that. (By the same token you may have trouble running an application that was installed on drive C if the drive now shows up as F.)

3

There are lots of reasons that can happen, but without more information it’s impossible to say what could be the culprit.

  • The old computer used BIOS/legacy boot, but the new one is UEFI
  • The old one was UEFI, and the new one needs the correct EFI boot path added to the list to find the bootloader
  • Bios is set for AHCI instead of RAID
  • Bios is set for RAID instead of AHCI
  • The drive needs to be added to the list of boot devices
  • The proper EFI boot loader is found, but the OS fails to start for any huge number of reasons
  • The old drive is not hooked up correctly, and so is not recognized by the computer
  • For other reasons the old drive is not functional
  • There is something else with higher priority in the boot list that is booting first

Installing a new copy of the OS onto your M.2 drive should work to boot the computer. If the old drive is functional, then you should be able to read it from the new operating systems. That might not be possible if the drive was encrypted and you don’t have the recovery keys. If the drive is non-functional for temporary or permanent reasons, then it will not be readable until you correct the problems.

If the drive is readable, copying the data off it should be easy. Go into \Users\Saint_Cad\Documents, etc. and copy the files to your new drive.

It is probably not possible to run applications installed on the old drive if you are running from an OS that booted from the M.2 drive.

4

It doesn’t show up as a boot drive.

Threw on an old hard drive I had lying around and it boots up fine.

5

It does not show up at all? I guess I would boot from an alternate drive, as you did, and see what errors are reported that might indicate why it is not readable. Or, perhaps you meant that the drive is OK but it does not show up in the EFI boot menu… in that case you can try to fix the boot path and/or boot loader, again by booting from alternate media first.

6

Doing that and it comes up as a second drive fine. Right now copying all of the data.
Is there a way to run a repair windows update without wiping the drive? Like I said, I will eventually run a clean install of all of her software on the new M.2. Just looking for a “right now” fix if one is possible on her old drive.

ETA: I’ll hop into BIOS as soon as the files are copied and see what happens.

7

for MS Windows you can (typically) fix it by following the following procedure: