Other HDDs not detected after losing MBR

Could someone please explain to me how MBR and GPT work in relation to managing other hdds?

Here's what I mean: I recently lost a main HDD, with a MBR (NTFS, windows). I restored that hdd along with it's MBR from an earlier drive image. After booting to that OS, I noticed that a couple of externally connected hdds are no longer detected (and show up in windows disk management as uninitialized -> boot record missing or corrupt).

Does this mean that those HDDs had their boot records stored on my C drive!? What kind of bollocks is that? One drive fails and it corrupts others?! (I think those external drives were initialized with Windows 7's Disk Management)

Follow up 1: How do I initialize a HDD so that it IS completely independent of any OS, and has its boot records and whatever else WITHIN ITSELF?

Follow up 2: If you have windows in your C drive, and afterwards you also install windows in your D drive, and anything regarding your C:\Boot gets corrupted, your D Windows also no longer works.
How do I install a second windows so that it is INDEPENDENT of any other drives or OSes on the system?

All I know is that if I remove all hdds but one, and install win on it, it is independent after I re-attach the other drives. But of the HDDs / SSDs / M2 SSDs are internal in a laptop, I can't always take them out.

PS: Is there any software that specifically recovers MBRs? Recuva for instance seemed to straight up go to recovering files.


You should just be able to right click on those disks and initialise them, the boot record has nothing to do with disks which aren't bootable.

You can install an OS to a second disk and have it's boot record on that disk also, but you can only boot from one disk, so you would have to change the boot order in your bios each time you wanted to boot in to a different OS. Generally it's easier to have all the boo records on one disk and if it gets lost or corrupt or whatever just make a new boot record.

Actually you should check that, I can't remember if initialising the disk will wipe the file system table or not. If that's the case there should be ways of repairing it, pretty sure you can do it with gparted on a linux live cd.

I initialised one of the hdds, and it was empty (though it's not really empty). I'm now waiting on Recuva.

I would really like to know how do I specifically tell a windows installation to install the boot record on the partition it is installing itself on.

You have to set that disk as the first hard drive in the bios boot order, windows will always install the boot record to the first disk

Oh, that makes sense.

The strange thing remains though, that by recovering a MBR on your C drive, you can somehow corrupt an external NTFS GPT HDD which has no OS on it or anything to do with C.

The only thing is that the HDD was originally set up with Windows Disk Management; not sure if related.

The unresolved issue seems to have been related to the external hdd usb adapter(s).
I have two different usb3 startech ones (on both of which the hdd used to be recognized just fine).
Hdd usb adapter 1: sees the hdd as uninitialized no matter which usb port I plug it into.
Hdd usb adapter 2: sees the hdd as uninitialized in 3 ports, and works normally (recognizes hdd) in the 4th port.

It seems to be related to the driver installation of the adapter; though I have no idea how things can get screwed up this way (and also how it won't work when booting from a recovery dvd instead of the OS it was installed on). I also tried uninstalling the adapter from device manager and it seemed to still show as uninitialized after plugging it in again later and re-autoinstalling.
I ended up using a different usb hdd enclosure/adapter.