Vista - no sound at all....

hello,
i recently purchased vista ultimate x64 and did the downgrade from xp pro sp2. computer ran like a dream in the customized version of xp i was running. now the system will not play sound...at all. proper drivers are installed, have tried it in media player and itunes and from the sounds window in control panel. system specs are as follows...
Asus m2n-e sli motherboard
AMD 3.0ghz x2 duo core
4 2gig sticks of g.skill memory
Western Digital 7200rpm 320g sata hd
Western Digital 7200rpm 250g sata hd
Ultra 500w sli power supply
2 xfx 8600 gt xxx 256mb running in sli
Linksys wmp54g wireless pci card (which is having some packet loss issues)
Coolermaster 690c case
DCLCD 22" widescreen lcd monitor
Saitek eclipse keyboard
Black Microsoft 3 button mouse
Acoustic Authority 2.1, a-3780rb 180 watt sub

i am using on-board sound because my currently unplugged turtle beach rivera does not support 64 bit os. the onboard sound is c-media cm6501 like sound device. i used the driver cd that came with the mobo and it had x64 drivers that windows recognized and installed. driver version is 5.12.08.1701 (lib v74) and yes i checked the manufacturers website and tried the latest driver they have on there with the same result. the speakers work when plugged into other things and i have tried all 6 audio ports on the back of my pc just in case vista switched them around. can anyone tell me anything i have not already tried?

sorry for double posts. is the problem with packet loss from linksys wireless card.

IF you have changed from a sound card to on board sound you also have to make sure you turn on the onboard sound from the BIOS

Check the device manager for problems. Verify in control panel under sound it is installed. Make sure its not muted. If on-board sound, make sure the BIOS has it enabled. If a sound adapter, verify the on-board sound is disabled.

the sound is enabled in the bios and the old rivera was taken out before the vista install after a short uneventful drivers search. the card is properly installed and vista says it is working, sees the audio going out of the card but does not acknowledge that any jacks are plugged in, they clearly are. nothing is muted. nothing is even turned down, the music i am playing at the moment with the volume levels should be breaking windows and have the police at my door within minutes. any other recommendations?

Did you install the chipset drivers for your OS?

let me put it this way there is not a single component in device manager that vista does not recognize and have drivers for.

does anybody have anything? anything at all? i need to have my music back. my ipod does not crank out enough power thru the tiny ear buds....

Have you gone into the speaks properties and checked the Level tab, to ensure the volume levels are all up?

This is what I'm refering to:

so the turtle beach sound card is not in the system?

if it is...
did you go to the sound properties and set the default device to play back through your on board sound?