Microsoft announced a new version of Windows XP called Windows Fundamentals for Legacy PCs. It's a stripped down version of Windows XP for old computers.
Microsoft says that there are many legacy systems that are not capable of upgrading to a full blown Windows XP install, and there are more systems where users are hesitant to upgrade. With Windows Fundamentals, Microsoft says that old systems will be able to receive all the latest security features and updates of recent systems, without having to sacrifice performance. Unfortunately, Windows Fundamentals will be limited to what applications it can run. Microsoft says that the OS is capable of running security tools, management software, and several document viewers. Larger applications will need to be run from a server. According to Microsoft: