The hack works by making a few minor changes in the registry of a Windows XP machine and works by basically tricking the automatic update servers at Microsoft into thinking the OS is Windows Embedded POSReady 2009. The OS is based on Windows XP Service Pack 3 and it will continue to get security updates from Microsoft until April 2019.
To apply the hack, create a text file with a .reg extension and the contents below:
Windows Registry Editor Version 5.00Run it by double-clicking in Windows Explorer. After this is done you'll be able to launch and run Windows Update. It should be noted that there’s no way of knowing how long this trick will work -- Microsoft could update their servers to put a stop to it at any moment. Also, because you’re installing updates for a system other than Windows XP, there’s the possibility that not all updates will work as intended. But for those still wanting to squeeze a little extra life out of their Windows XP machine it may be worth a shot.
Update: Microsoft has issued the warning below to users that this hack may cause serious functionality issues, as well as not fully protecting a users XP machine. Definitely use caution if you try this at home!
"We recently became aware of a hack that purportedly aims to provide security updates to Windows XP customers. The security updates that could be installed are intended for Windows Embedded and Windows Server 2003 customers and do not fully protect Windows XP customers," a Microsoft spokesperson told ZDNet. "Windows XP customers also run a significant risk of functionality issues with their machines if they install these updates, as they are not tested against Windows XP. The best way for Windows XP customers to protect their systems is to upgrade to a more modern operating system, like Windows 7 or Windows 8.1."