Stereomix not available for Sigmatel

I have reinstalled XP Media Center Edition, and installed SP3, and now I am finding that my "Stereomix" or "What you hear" choices are not availalbe under sound recording. I have researched and found that this is done on purpose by the manufacturer and can be fixed by purchasing some other software. My system is Dell Deminsion 8400 Desktop, Sigma Tel High Definition Audio CODEC Driver Version 5.10.0.4995
If anyone has any ideas or workarounds i would really appreciate it!

 

Since I never rec'd any replies, just thought I would give an update to this post.... I called Dell, only because I have complete care warranty on my laptop... he walked me through with a driver. It took a very long time for the tech to figure out the correct driver, he tried 3 different ones. just for anyone else with the same problem..