How do I format this dynamic disk? (or get rid of this parition)

They are.

Berton said:

My solution in such a situation is not Windows-based when Windows can't do it. I use either the Linux-based bootable GPARTED [GNU Partition Editor] LiveCD made from a downloaded .iso file or the same program on my Linux computer to wipe drives completely clean. I just downloaded the MiniTool Partition Wizard to try at next opportunity.

I've been considering doing that, however reading the rest of the posts, it seems like jumping into that is a bad idea.

cereberus said:

Assuming OP gets over that hurdle (testing pc boots with drive 1 temporarily removed)

I didn't even have disk 1 when I originally broke things and I could use Windows just fine. Although after installing Windows on this disk 1 (I never uninstalled Windows on the other disk), I get the option to boot into either this OS, my old OS or a third Windows that simply does nothing when I try booting into it and it shows no volume number. My plan is to use disk 1 for my OS and disk 0 for another OS/backups.

Megahertz said:

First thing you need to do is to find out what type of drives you have (MBR or GPT)
Second is to make drive 1 self boot able.
third is to clean drive 0 and format it to be used as a data drive.

Lets find out if the drives are MBR or GPT

Open a CMD window as administrator and type:
diskpart
list disk (it will list all drives. Identify windows drive number) Does it has an * on the GPT column?
Sel disk 0
list part (does it has a EFI FAT32 partition?
list volume
exit (to exit diskpart)

Use the snipping tool to take a snapshot of the CMD window.
Paste the image here.

Probably worth noting this, not sure why there's just a missing disk in disk management:

The only two drives in my computer are disk 0 and 1, not sure what this disk is. Maybe it was reading my old 500 GB SSD twice, judging by the size and the fact that it's dynamic. Maybe this is the broken Windows that is in the OS selection screen when I boot up my pc.

Megahertz said:

Let's do the second step that is to make drive 1 self boot able. We need to create a EFI Fat32 partition and install the boot manager on it.
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Report

It's getting late, I would rather not do this today. I'll try tomorrow, although I am scared due to not having backups of the stuff on here. I really should back some stuff up, but I don't have a large enough external drive.

Megahertz said:

@IDKAGN, did you succeed on creating the EFI partition on drive 1?

Yes! I did what #2505103 told me to do and my primary Windows 10 booted without issues. I have disconnected the other drive in my BIOS and set it to boot after my primary SSD. Somehow it also seems to have removed the extra broken entry for Windows 10 as I did not have to choose an OS when booting my computer.

Now that my SSD with my primary Windows 10 boots on its own, I assume I should try this:

Berton said:

My solution in such a situation is not Windows-based when Windows can't do it. I use either the Linux-based bootable GPARTED [GNU Partition Editor] LiveCD made from a downloaded .iso file or the same program on my Linux computer to wipe drives completely clean. I just downloaded the MiniTool Partition Wizard to try at next opportunity.

But I'll wait for responses first, just in case it's a bad idea.

Megahertz said:

You have created a new boot manager on drive 1 where it also has the C: partition.
The other boot manager on drive 0 is still there, with the extra broken entry for Windows 10, you're just not using it.

What do you want to do with drive 0? I suggest you clean it to get rid of the dynamic partitions.
Before you clean it you have to disable the recovery partition on drive 0 and create one in drive 1.

Are you able to save all data on drive 0 on drive 1 so we can clean drive 0?

I'm planning to use it for either a second OS (maybe linux mint?) or archives of old software and other media.

How can I create a recovery partition on drive 1?