I do have vista 32 installed on the other PC for my dad. But I find it too complicated to use as compared to Win XP. May be because I am used to XP. BTW, its is heard that Vista was not successful and will be soon replaced with the other OS.
I used Windows XP for my computer. It is good one operating system for me and never create any type of problem for me.
I'm quite happy with Vista. I work from home so my home systems are quite high spec with a server running in the background as well