Is it possible to enable hibernation when dual booting Windows?

"I can't provide a detailed and simple answer, because I never multibooted more than one windows, but you have to options:

This is ""back asswards"" kind of solution. First install both windows instances you want, then slice off a 5-10GB partition and install some flavour o linux. GRUB or LiLo or whatever will overwrite the windows bootloader and this will allow you to do what you want (It works for windows and ubuntu - I can hibernate one and then boot into the other; works both ways).
Now, if you're not interested in linux, edit grub's config to remove linux and leave only windows, then proceed to remove the linux partition and extend the others over the free space.
If you're not afraid to do your research: It's possible to install GRUB to replace windows bootloader without installing any linux distros. As I have never needed it, I don't know how to do it, but the information is out there."