I have an unusual case. I'm not trying to partition drives or anything, I have separate physical drives for Windows and Linux. Being a new machine and all, I have UEFI.
Last time I attempted to install Ubuntu 12.04, it worked fine but it destroyed my windows install. Changed the format of the drive or something and messed up the MBR. This was 6 months ago, so sorry for the lack of technical insight -- my memory is a bit off. Wasted a lot of time reinstalling Windows, and I gave up for awhile.
Now I'm trying it again (after 12.10 was a technical disaster, repeated unity crashes and whatnot) but I currently have my Windows drives disconnected so my Ubuntu install can't mess it up.
I figure my future bootloading will involve selecting which drive to boot from, but I'm worried that GRUB might take it upon itself to mess around with my Windows drives the moment I boot from it. Is there any way I can be certain that I won't have my Windows partitions corrupted again? Last time it took over a day to reinstall everything, this time I suspect it'll be much longer.
On the other hand, I really don't want to be physically unplugging and replugging drives whenever I want to switch operating systems. Selecting drives is weird, but I can at least live with that...