There is no huge difference between Windows XP Professional and the Reduced Media Edition. There is no way anyone can look at the mere desktop and deduce that they are using the Reduced Media Edition. Microsoft has bundled Service Pack 2, which includes the Windows Security Center. Again, exploring the control panel, we see the usual suspects including Windows Firewall and a few others. The only indication that a user is using Windows XP RME is during the welcome screen after the OS is installed. The welcome screen clearly reads: “This reduced media version of Windows XP includes standard Windows functionality, with the exception of certain Windows multimedia technologies.” Also, peeping into the system properties, the system is labeled, Reduced Media Edition and clearly states that the system is at the Service Pack 2 level.
Users can’t play any .WMA files. Windows doesn’t recognize its own file format, and prompts the user to use the web to find the appropriate application which will play the file. In addition, since there is no media player of any kind in this version of Windows, you can’t play any type of music or video media.
Microsoft was ordered to remove more than just Windows Media Player from the OS; the EU decision required Microsoft to remove a total of 186 files. You can read more on Microsoft’s Implementation of European Commission Decision
here.