This is very interesting, but it can’t last long. I’m sure Microsoft knows about it by now, and will find a way to cut it off. Soon.
Registry hack enables continued updates for Windows XP
Summary: A single registry setting makes Windows Update think your XP system is Windows XP POSReady, which will receive updates for another five years.
By Larry Seltzer
http://www.zdnet.com/registry-hack-enables-continued-updates-for-windows-xp-7000029851/