XP was tolerable. Performance wasn't too bad. Being a vector for viruses wasn't fun, but if you watched yourself you could usually get your work done. When my elderly laptop died I bought a nice refurbished HP desktop that came with Vista. There are no shortages of rants on Vista, so I'll be brief. It seemed to be a RAM hog and applications froze and died on it just too much - even Internet Explorer. Man, at least the software made by the same company that made the operating system should work.