On my last desktop computer, I had a successful multi-boot setup with Windows XP, Vista, Ubuntu 8.04 Hardy Heron, Ubuntu 9.10, TinyMe, and heck, even had a Fedora install before wiping it to try PCLinux2007, then Linux Mint. (Which I also later wiped because it seemed like a boring appeal to Windows users.) I would have tried OSX86 too, if I didn't run out of room on my 128GB Seagate HDD for more virtual partitions big enough to hold an OS. I already had six OSes to play with anyway!
And let me tell you, it was not easy to pull off. GRUB still couldn't load Vista installs at the time, so I had to piggyback every OS on Vista's boot loader with EasyBCD to edit the BL, make sure every OS had its own boot loader installed to Root, (Otherwise it'd wipe Vista's on the boot sector, and I'd be back to square one.) and it still wasn't THAT easy, contrary to its name. My partition table was a mess.
I don't imagine Microoft has made multi-booting less of a headache for the end user, now that you have to put up with SecureBoot and all that. It's like they regularly inhibit your freedom of choice with backwards design choices under the hood, knowing full well you're going to multi-boot whether they like their diminishing presence on the desktop or not.
That's why I want to build a PC for Linux, maybe dual-boot it with Windows 10 if I don't get mad at SecureBoot first, or buy a mid-end Windows 8 PC for running games that don't get Linux ports. So when I said headaches, I really meant it. It was load of convoluted bullocks and flaming hoops I don't want to go through again.