To further comment on this, the OS the parent is referring to is Windows Fundamentals for Legacy PC's which is based off Windows XP Embedded, to be a replacement for the 9x/2000 machines that volume license customers with SA contracts may be using. It runs on less memory and processor and is up to date on patching (as up to date as XP can be). While this wasnt intended to be a full featured os (I believe its more for remote desktop and holding over old hardware until companies can upgrade), I have used it in vmware and have not had any major issues with it. http://www.microsoft.com/licensing/sa/benefits/fundamentals.mspx