Audio and Audio Service

I am suffering through a problem that I see others who are suffering as well.
I have read through the postings on the discussion group regarding the audio
service in Vista.

I bought my laptop (Dell Inspiron E1705) back in February with Vista Home.
Everything worked as it should. I upgraded to Vista Ultimate this week, and
now I have the red X by the volume. Here is what I have done so far:

Contacted Dell who proved no help, other than providing me with the audio
driver, which I have deleted and added a couple of times. They recommend I
transfer to the fee based system.

I have gone through services and attempted to start Windows Audio and
Windows Audio Endpoint. When I try to start Audio, I get an error that says
it cannot start and returns Error 1068: The dependency service or group
failed to start.

Audio Endpoint says: it cannot start, and returns "Error 0x80070002: The
system cannot find the file specified," although it does not tell me what
file is missing.

I have searched to make sure I have the audiosrv.dll, and I do

I have run the sfc/scannow, and the log does not tell me that there was
anything repaired

I cannot select a restore point to go back to since this all happened when I
upgraded Windows. It is frustrating that an upgrade within Vista--not from
XP to Vista--would leave such a mess.

Is there something else that I can do that I haven't already done? To be
honest, I can open the registry, but I have no ideal what I am looking for
once I do and would prefer not to do that.