Rodny, MSI has Vista drivers for your onboard sound and a couple of other components
here. I wouldn't trust Vista to automatically have gotten these for you. Realtek seems to have even newer drivers
here, but I'm not absolutely sure since Realtek doesn't state what chipset they're for...but Vista was update 10/22/07.
When you say the system worked with XP, were you using the SB Live card or the onboard audio. According to the manual (p. 8), you need to connect specific jumpers to enable the rear audio ports on the K9MM-V. Just trying to confirm the easy stuff, first.
Also, make sure you go ahead and pull that SB card out, if you haven't already...since you don't have drivers, no sense in letting it try to confuse us or Vista while we troubleshoot.
Looks like MSI also released a BIOS update a few weeks ago...may be helpful.
One thing that's got me confused is MSI says that mobo is capable of 6 channel audio output. Problem is, it only has 3 audio jacks on the back, which are supposed to be line in, line out, mic in. The manual doesn't say how to reconfigure for what I would assume is l/r, c/sub, sr/sr. Maybe it's in the BIOS settings, which aren't completely covered in the manual? Partly answered my own question...in the FAQ for the K9, it shows what I assume is the Realtek driver interface. Wonder if configuring for 2 channel gives you the line input back.
Regarding Vista audio, as part of its "improvements", MS took away things like WAV control. They went to a scheme where you control audio volume by application instead of device. You can kind of still get to the device level controls, which you'll have to do since REQW can't access the controls directly under Vista. Right click on the speaker icon in your toolbar and select "recording devices". The available devices, such as "line in" should show up there. If you don't see your "line in" and you've checked the h/w settings/drivers I mentioned above, right click in the white space and make sure the "show disabled/disconnected" options are checked. If that doesn't work, you'll need to go to the device manager to try to add them back.
If all else fails, a SB Live External USB is only $50 at your nearest Circuit City. There's a line input drive level issue where even at max gain, you can only get the REQW soundcard cal I/O levels within about 10-12db instead of the suggested 3db window, but it's close enough. I've compared the same sound card/cables/adapters on separate Vista and XP machine and the cal files came out virtually identical despite the Vista/REQW calibration level issue.
Well, one other thing...you could try posting/searching the MSI forums. They require registration to search, or I'd already have done it for you.
-Brent