Windows 7: Sound problems

I'm new on this forum so Hello everyone

Few days ago i installed my new windows seven professional x64 and i can't solve my sound problem on sistem 5.1
My motherboard is from intel => DP35DP and my sistem is Logitech X-540
i've tried to install all latest drivers from my motherboard and i have sound only on my headphones... even with IDT,sigmatel or realtek
also i tried this topic Intel IDT Audio Driver will not install
but without any luck...
i searched all kind of things on google but nothing could help me...
also at device manager "Pci Simple Communications Controller" is unknown...and i can't find any drivers for it

Sorry if is already another topic on this subject
Tnx

In device manager, right click on the pci simple communications controller, click properties, then click the details tab. Click on the dropdown arrow and select Hardware ids, you'll see a code like PCI/VEN_8086&DEV_27D8&SUBSYS...

I have an Intel DP35DP motherboard. I just disabled the PCI communications device in the Device Manager. That was a year ago and everything works OK.

The sound driver for Widnows Vista/Windows 7 for the SigmalTel (now called IDT) is on the Intel site's downloads for the DP35DP motherboard. These drivers work without problems and even provided the "System Mixer" function so you can record streaming audio.

If you have the correct IDT driver installed, FROM THE INTEL SITE, first thing to do is check the playback device in the Control Panel/Hardware and Sound/Sound Panel. The speakers should be selected as the default playback device. Plug the headset into the rear GREEN speaker jack and see if you have sound. If you do then the problem is in the speakers. If not, go to the Device Manager and "Uninstall" the IDT sound in the Device Manager (DO NOT uninstall the drivers) then restart the PC and when Windows starts it will detect and reinstall the Sound. Check to see if this fixes it.

Idt driver is installed from they official site , also i made my config to 5.1 and set speakers as default..but still doesn't work... if i plug my headphones in rear green they don't work,only if they are plugged in front panel (special for micro and headphones)
after i did "uninstall" from device manager like u said,he got his own drivers again but still no sound in speakers
strange because on xp pro, i didn't had any problems with sound...

@bill2
PCI\VEN_8086&DEV_29C4&SUBSYS_50448086&REV_02
PCI\VEN_8086&DEV_29C4&SUBSYS_50448086
PCI\VEN_8086&DEV_29C4&CC_078000
PCI\VEN_8086&DEV_29C4&CC_0780

i guess is 8086 and 29C4 for dev...

this PCI Vendor and Device Lists for ven
and i'm lost here...don't know what to do...
and this is PCI Vendor and Device Lists for Dev , i tried to install but says "This operating system is not supported
Setup will exit."