According to The Register it is possible by using a piece of software named NTSwitch [ntswitch.zip] by hungarian company 03am.com. This software according to 03am was designed to show that basically the NT based Windows OS in either desktop or server variants are the same and that the differences only result from some registry keys. Read more...

Furthermore by quoting some 'testers' it seems possible to switch XP Pro to .NET server or vice versa. This may lead to a memory leak but according to The Register it works nonetheless... I attempted this on .NET Server and have sucessfully converted Build 3615 to Windows XP Professional. Using an app called NTSwitch, .NET now thinks it is a workstation OS , in this case, Windows XP Pro. All of the features of XP that were disabled, such as fast user switching, the welcome screen, and DirectX now work perfectly. I have personally always got much better performance out of .NET than I have out of Windows XP. This program works by changing certain entries in the system registry to trick Windows into thinking it is a workstation OS. Once you run this program, you can reboot, enable fast user switching and the welcome screen from Group Policy Editor, gpedit.msc from the run command, your boot logo will be changed to that of XP Pro and many other things. For full details warp 2 The Register via the above link. Related links: Windows NT -> NT Server The original findings of NTSwitch working @ ADTW FileMirrors.com