I have a nice work laptop which runs a custom Windows 8 image. The machine has an enormous hard drive, and it struck me that it would be really good if I could dual boot it with a 'personal' image so that I can have my own applications, internet etc on it.

The laptop is a Lenovo ThinkPad and it has a UEFI bios and I've not used these before. The drive is divided up into various partitions, including system, recovery and 'OEM'. It also has a small SSD (16GB) although I'm not sure what this is for, and it is also labelled as 'OEM'. I tried shrinking down the main primary partition to give me a decent amount of space and then installed Windows 8.1 on to it using a USB stick. From the reading I had done, it seemed that all I would need to do is install it and it would automatically set up a dual boot.

Everything seemed to go OK and sure enough I got the dual boot screen come up. It would boot my new Windows perfectly but when I tried to boot the work installation it didn't load - it tried to do an 'automatic repair' which failed. Looking at the partitions in diskpart showed it as simply a 'RAW' partition. This was a bit of a problem as I now couldn't boot my work image at all!

After some playing around in the BIOS I found that the boot order had 'Windows Boot Manager' first and the hard drive itself listed second. If I changed the order so that the hard drive was first, I could then boot the work image but when I looked in the disk management screen my new installation showed as a 'RAW' partition!

So somehow the boot order seems to be causing one or other of the primary partitions to become unreadable which is presumably why it won't boot. I don't want to break the work image if I can help it... but I'd love the dual boot to work.

Does anyone have any ideas why this is happening and what to do about it?