Winload.exe missing or corrupted, partitions show as unknown after SteamOS Installation

I've just installed the new SteamOS iso and went through all the expert install menus and decided to install the bootloader to the main drive (my ssd with windows 8.1) and i could restore it later. Anyway, I went through the whole process and did the post_install.sh and then logged into steam etc. etc. and then went to go back to windows via the grub boot menu. 

So this is where the problem occurs.. I get a message saying that boot needs fixing and winload.exe is either missing or corrupted 0xc00000e. So I rebooted into the install media and attempted a startup repair and get a sudden reboot, so then i went into cmd and tried all the bootrec commands. Most were successful but no windows os are found and one or two of the commands say element not found... 

I then boot into a gparted live usb which shows three partitions that say 'unknown'. So that gets me to thinking they are corrupted somehow. I would like to recover the data but dont really know how when windows cant access the drive and linux cant recognise them. 

So questions, are there any fixes i havent tried yet? Is there  a way to recover or restore the windows partitions? Any ideas would be great as I've been at this all night and i give in until the morning... 

SteamOS runs pretty well now for those wondering. And installation was pretty straightforward even if I messed up the mbr

I'm now in the process of retrieving any data I can get hold of then I'll reinstall the os. At least I kept most of my applications and games on my 2tb HDD. I might have to reinstall black mesa and ac4 (plus a few applications) but thankfully I didn't get very far in bm and ac4 is all stored on ubisoft's server. So there are some advantages to DRM (although I still can't stand origin)