Boot issues abound (error 0xc0000001)

So I've been double booting Linux Mint and Windows 8.1 for three years until last week when Steam broke my graphics driver. Since then I've had a classic case of https://xkcd.com/349/, where attempts to repair a minor issue went spiralling out of control. Long story short, both Mint and Windows are down, and everything is crashing and burning.

My priority is to fix Windows since I could just reinstall Linux (I have some applications in Windows that I would rather not lose).

Well, Windows is BSODing on boot with the error code 0xc0000001, which means something is wrong with my boot files. What I've tried:

Using a Windows live usb:

• Automatic startup repair and bootrec did not work.

• Chkdsk detected errors but said the disk was write protected and so cannot be locked. Diskpart said nothing is read-only. I ran chkdsk on C: and it took the whole night to run but the issues persisted.

• sfc /scannow detected issues but could not fix them. CBS.log only had information from weeks ago.

• dism says the /online option does not support servicing windows PE.

• This is already after a system restore which, along with boot-repair, got Windows back in the grub menu (did I say I lost Windows in the grub menu?)

Using a Linux live usb:

• boot-repair did get my grub back but that's it.

• ntfs-3g did not find anything wrong.

I'm kind of at a loss as to what to do now.