I can still access all the files with Command Prompt, so I'm pretty sure it's ok. DISKPART also reports that all partitions are "healthy", there's just a problem with it booting which I can't work out.
I've tried all
bootrec commands..
/fixmbr - Didn't fix.
/fixboot - "Element not found."
/scanos - Didn't fix.
/rebuildbcd - "Element not found."