http://www.zdnet.com/registry-hack-e...xp-7000029851/
I have a bunch of windows XP VMs, and don't plan on ever moving them to a later version of windows. So this sounds like it could be promising. At least until msft figures out a way to block it.Williams says that the hack, included just below, makes the system look like Windows Embedded POSReady 2009 which will continue to receive updated until April 9, 2019.
Also, this may mean your machine gets updates that are not compatible with regular XP. So beware of the downside...