No sound in Windows XP (Mac side fine)

Question

As many others have experienced, I have no audio in Windows XP. I had hoped my upgrade to Leopard and its Boot Camp drivers would fix it, but no joy.
Here's what I've tried:
- re-installing the device drivers individually. They seem to install correctly, but Control Panel/Sounds and Audio Devices still says "No Audio Device".
- removing/re-installing/repairing my Boot Camp drivers (this started with Beta 1.4, so I tried everything there; then it continued in Leopard, so I've tried the same again with the new Boot Camp).
- running the 'kb835221' fix most recently in Leopard, but no joy there, either.
If I click on Control Panel/SigmaTel Audio, I get a RUNDLL window with a white X on a red background. The text says "An exception occurred wile trying to run "C:\Windows\system32\shell32.dll,Control_RunDLL "C:\WINDOWS\system32\stacgui.cpl",SigmaTel Audio" followed by a rundll32.exe - Application Error window that says "The instruction at "0x1003e494" referenced memory at "0x00c13fd4". The memory could not be "read". Click on OK to terminate the program" When I click on OK, this is followed by another similar window. Then it's done. (Now, I've been around Windows enough to know that these most likely just go with the first error - not that there's anything wrong with my system's memory; but I included them for detail, just in case.)
Also, I have *no yellow exclamation points* in the Windows Device Manager. Everything says it is operating correctly. However, under the Sound, video and game controllers section, I have a Legacy Audio Drivers and several Codecs, but no RealTek driver. Even after installing the RealTek driver several times, it never shows up in the Device Mangler - uh, I mean Manager
Whew! So, if you've made it to here - do you have any ideas for me, short of re-installing my WinXP??? If it comes to that, I'll have to live without the sound at this point... Please, oh sound gurus, I beg for your help!

Answer 1

OMG, I finally found it!!!!! My problem is apparently a common Windows XP issue, and has no specific relation to Boot Camp or the Mac:
I was missing the 'Plug and Play Software Device Enumerator' device from 'System devices' in the Device Manager. Once I got that installed, my audio started working fine - no reboot was even necessary!
Here's a link to the details:
http://www.annoyances.org/exec/forum/winxp/t1066427444
And, here are the basic steps:
1) Go to System in Control Panel, Hardware tab, Device Manager button.
2) Click the + in front of 'System devices' (near the bottom), and look for a line that says: Plug and Play Software Device Enumerator
This fix will only help if you are missing that line, or if you have a yellow exclamation point on that line! If you have that line, and there's no yellow exclamation point, then stop here and look elsewhere - you've got a different situation.
Okay, now that you've confirmed that you're missing the Plug and Play Software Enumerator, or that it's broken:
1) Make sure you have the following two files in Windows (do a search - they should be there):
* streamci.dll
* swenum.sys
You don't need to do anything with them, just make sure they're there.
Then:
1) Copy machine.inf from WINDOWS\inf to a temporary location
2) Edit the temporary copy of machine.inf - remove the line that says "ExcludeFromSelect=*", and save the file
3) in Control Panel, choose "Add Hardware"
* at the 'Welcome to the Add Hardware Wizard' window - click Next
* at the 'Add Hardware Wizard' window (when it finishes searching) - click 'Yes, I have already connected the hardware', then click Next
* scroll to the bottom of the list of 'Installed hardware', and click on 'Add a new hardware device', then click Next
* click 'Install the hardware that I manually select from a list (Advanced), then click Next
* click 'Have Disk...', and browse to and select the edited machine.inf file
* scroll down in the list of 'Common hardware types', and click on 'System devices', then click Next
* under 'Manufacturer' on the left, select '(Standard system devices)'
* under 'Model' on the right, select 'Plug and Play Software Device Enumerator'
* click Next
Once the installation is finished, and the Device Manager shows the Plug and Play Software Device Enumerator under 'System devices', the audio should now work (no reboot required) - ah, joy!
Again, for more details, or if you have some questions, check the link above - it's got good information.