So, I installed Windows 8 developer version today and I didn't see it overwrote my Windows 7 installation. There was a windows.old folder, and removed W8, and put back W7 via the way MS said. Then did a few SFC /scannow 's to fix any problems. Everything seems to be running like before again; but I now have a strange extra disk that's 8GB big...

Also tried on Kubuntu, but can't unmount/format or do anything at all with it... Does anyone have an idea how I get rid of it?

You can't format the drive because it's not partitioned. You can try running "sudo cfdisk /dev/sdd" to partition the drive.

The drive appears to be connected to your onboard SATA II controller, is the drive detected by BIOS? Have you changes your BIOS settings somehow? How many drives do you have in your PC?

Quote from MadCatX :

You can't format the drive because it's not partitioned. You can try running "sudo cfdisk /dev/sdd" to partition the drive.

The drive appears to be connected to your onboard SATA II controller, is the drive detected by BIOS? Have you changes your BIOS settings somehow? How many drives do you have in your PC?

I can't partitionate it, already tried.

The drive is not visible in the BIOS. I havn't changed my BIOS settings for some weeks now.

Quote from cargame.nl :

http://forums.overclockers.com.au/showthread.php?t=762385

Thanks, but my express-gate isn't turned on...

Perhaps you can load BIOS default settings or remove the CMOS battery.

Quote from MadCatX :

Perhaps you can load BIOS default settings or remove the CMOS battery.

I managed to fix the problem. I have some option in my BIOS called drive xpert or something, which was on auto. I simply disabled it, and it's gone. I can't imagine how Windows 8 has anything to do with it as I didn't change the setting. Anyway, thanks for helping guys!