Audio Problem with XP Media Center Edition

I recently installed Lexicon Omega Desktop studio on my Dell Inspiron 9300 with Windows XP Media Center Edition. After installing it, my sound stopped working. I uninstalled Lexicon. I checked my Sigmatel C-Major Audio Driver and it said it was enabled but not yet started (also states device is working properly). It is not working though (it is not a problem with my speakers because my speakers make a beep sound for every windows message). I googled several things about this problem and tried to update the driver for Sigmatel but it didn't work. I tried uninstalling and re-installing it but every time I got an error message at the end. "No Audio device" shows up in Sounds, Speech, and Audio Devices. When I click on volume control, it says no audio mixers available. when i go to control panel and add hardware like it suggests, no audio mixers come up to be installed. There are 2 plug and play software enumerators listed under system devices. should there only be one? Also all of the Microsoft Kernel programs have yellow exclamation points next to them in Device Manager. "Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42)" comes up when I click on properties for them. any help would be very, very appreciated. thanks.