I've recently re-installed Vista, the 32bit version this time so I don't have the compatibility nightmares I found with the 64bit version. (duel boot now so I still have XP as well)
However, one problem i've had since I built this new rig was that my AMD Athlon 64 x2 5000 CPU was running rather hot under XP, about 60-70C. I'd put this down to the bundled heatsink and fan being basic and made a note to self to upgrade the cooling when I could.
However, on Vista it stays quite happily at a much lower temp, between 45-55C. Is this normal and why? Is it just that Vista uses newer duel core CPUs better and therefore doesn't make them so hot or do I have a problem with XP?