Linux only. Currently a dual boot with Debian, and Linux Mint 7. I had Vista for a short period of time, when I bought this new computer, but alas, I accidentally erased it when I was partitioning for a dual boot. Silly me.
That was my experience when dabbling with Ubuntu and XP a while back so I prefer to think Silly Ubuntu than me.
Nope, in my case, it was all my fault.
When you have the option of using the free space you cut out of Vista for the new install, or the entire hard drive for your installation, and you choose the later out of habit, and not thinking, you deserve what you get, which is to wipe Vista off of the machine.
I did have some time this morning to reload, so now I'm back to dual booting Debian and Vista. This is my home computer. The office computer is pure Ubuntu (currently Jaunty).