Enable Multi-User Mode for XP's Remote Desktop

Before its final release, Windows XP's Remote Desktop function had a feature it now lacks: multi-user mode, whereby more than one person could log on and control the PC at once. When the final version of XP shipped, though, this feature was disabled, meaning if you log on with remote desktop, any other user must be logged off. Fortunately, there's a way to unlock the original functionality, but as won't surprise you it's a bit of a hack and definitely at-your-own-risk. The process is detailed by Riccardo Raneri in his blog, but basically involves downloading an old pre-release version of termsrv.dll and making some setting changes. XP still has a hard-coded limit of three simultaneous users, but that's still a lot more than one. It's all here.