MacBook Air (2019) shows as "Unknown device" in Windows 10 when using Target Disk Mode

Question

I'm trying to salvage a MacBook Air 2019 that's fallen to the Big Sur upgrade bug. One of the last solutions I can feasibly try is putting the Mac into Target Disk Mode and accessing the files from another computer, deleting some files to make space for the Big Sur upgrade to succeed.

Normally, this is relatively easy with another Mac, but I don't have another Mac, so I'm trying to access the files from my Windows 10 PC using MacDrive and a USB C 3.0 cable. I know the cable works because the Mac shows up in Device Manager as "Unknown device" with the hardware id "USB\VID_05AC&PID_1800&REV_0101". I haven't been able to find a driver for this online.

Does anyone know what I can do to get this MacBook to mount on my Windows PC?

Here are the other steps I've tried to recover this MacBook, all of which failed:

• Boot into Safe Mode (doesn't do anything at all)
• Boot into Recovery and do stuff with the Terminal (doesn't work, Recovery doesn't accept the correct login and so none of the recovery tools are available)
• Reset NVRAM (doesn't do anything)
• Reset SMC (also doesn't do anything)
• Boot from an external macOS installation drive and do stuff from there (doesn't work, once booted into the USB an error shows up claiming that the MacBook doesn't allow booting from external devices)

Answer 1

You will need MacDrive 10.5 beta to read APFS.
If you had FileVault enabled, this will not work.
MacDrive cannot handle FileVault at all & cannot decrypt an encrypted drive.

You need another Mac with Mojave or High Sierra to use TDM in this way (because neither Catalina nor Big Sur will unlock FileVault over TDM), or you need to take it to Apple.

Answer 2

Turns out it was much easier to just get another Mac and mount the bootlooped Mac in Target Disk Mode.

After doing so, I was able to erase the system partition on the Mac in question in Disk Utility, leaving the data partition intact, and from then on, the data partition started accepting the correct encryption password. I was able to safely recover all my data, reinstall macOS, and restore it after.