So I have just used
gdisk to remove the MBR on my Mac's drive because I got annoyed that I couldn't access my fifth partition - but then learned I could with GPT. Now that I did the "conversion" (its rather just like erasing the MBR and overriding it with a
protective MBR) I am facing this one issue that just smells like it's trying to boot with BIOS/MBR although it isn't supposed to:
Couldn't find bootable drive - please insert drive.
Aka. it can't find it's partitio since the MBR is gone.
I don't have my windows install around, so I would like to know if I am able to change Window's boot mechanism from Mac OS? It's Windows 8 that's making the issue.