This week, Microsoft shipped the Release Candidate 1 (RC1) version of Windows XP Service Pack 3 (SP3), a near-final look at the last XP service pack. I've categorized XP SP3 as a long, final goodbye to an old friend, and booting into XP to install this update certainly brought back some nostalgic memories. But seriously, folks: It's time to walk away. There's just nothing compelling here when you compare XP with SP3 to its much newer and improved counterpart, Windows Vista.