That downgrade was an upgrade!
Vista was a disaster of an OS.
XP was more buggy than Win'2K until SP2 came out. After SP2, XP became a really good OS. People seem to think the 100 or so patches and updates since then are a reason to switch away from XP. I see it as a reason to stay with XP. They finally got all the bugs out! No other M$ OS is as finished as XP is.