Since the release day of Windows 8, I have been running a 64 Bit Pro copy that was downloaded through MSDNAA. I've not had any problems up until yesterday, when it decided to stop booting. Now it goes to preparing automatic repair, then diagnosing your PC, then 'Automatic Repair couldn't repair your PC'.

I can't use any of the advanced tools, because apparently I don't have an administrator account (which is news to me, I thought that my one and only account was an admin one).

My computer is setup to triple boot Windows 8, Windows 7 and Kubuntu.

In Windows 7, I can see the drive R: (which has Windows 8 on), but through explorer, I can't access it.
Apparently access is denied.
Trying to view any information about the drive just shows that its capacity is 0 bytes.

If I open a command prompt as an administrator, I can navigate to R: and browse files and folders, and copy them onto my Windows 7 drive, so no data has been completely lost thankfully.

In Disk Management, I can see details of R:
I can also run chkdsk on it.
It found errors the first time, and fixed them, but this hasn't fixed my problem.

It seems as if I need admin rights to do anything with the drive, even boot from it, but because I apparently don't have an admin account on Windows 8, that's why Windows 8 won't boot, or that's my guess.

Anyone got any ideas?