Hey there, interesting story.
I'd finished making the fixes, installed and booted Linux to test - ran game, launched OK.
Went to boot back into Windows to upload to Steam and Windows won't boot, spent the last 6 hours trying to figure out what the fuck has happened and it turns out that the bootloader and partition are corrupted - I can't recover the data. Naturally we have multi-tiered backups but still a nightmare.
Nice to know the whole linux/windows dualboot situation is as volatile as ever, more so now with all this EFI/BIOS shit thrown in.
TLDR: Working on it.