No other software is requiered. However, I know MCE has a specific DirectShow filter installed which handles DVR input streams. The filter's name is "Derypt/Tag", and its file is "encdec.dll" located in the Windows\System32 directory. When you start graphedit, and "Render Media File..." on your XP Pro machine, what filter comes directly after the source file?
This is important, since the <nternal graph filter> from AutoDVRconvert, uses this specific filter in its graph. If you find this second filter to be different on your XP system, it is still possible to make it work, only you have to create a filter set, which works on your system, with graphedit, and save it as XML file (XGR extention by graphedit) and put it in the directory where you stored the EXE file of AutoDVRconvert. After this, you should be able to select this XGR file in the drop-down-list "Filter Graph to use".
When making your own graph, make sure that you use the dump filter at the end instead of the video and audio render devices.
A quick walkthough:
Start grapedit. Select "render media file...", select your original DVR file which to convert. Now, when you press the play button, you should get the TV show playing back, including audio. If thits doesn't work in the first place... bad luck. If it does, stop the graph (stop button). Then remove everything from your graph, except the DVR source filter, and the 2 filters directy connected to this one. throw away everything after that (including the DVD decoders). Now, add the following 2 filters: "Dump" and "CyberLink MPEG Muxer". Both can be found via: Graph->Insert Filter->DirectShow Filter. When inserted, connect all the pins together (drag & drop).