DVRMSToolbox
This little application performs the work of converting the DVRMS files residing on your Media Center to MPEG files that can then be downsized and synchronized to your PSP using PSPWare.
You can obtain DVRMSToolbox for free from the Green Button Community at:
http://www.thegreenbutton.com/community/shwmessage.aspx?ForumID=26&MessageID=113435. (Look for the file called InstallDVRMSToolbox.zip.) Installation of DVRMSToolbox is pretty straightforward. It does require that you have the .NET Framework 1.1 installed on your Windows XP Media Center Machine. However, .NET Framework is freely available from http://www.microsoft.com.