Windows 7 - realtek ac97 no sound,but shows its working

Knowing my luck,I have overlooked a setting,but either way my sound is not working,i recently installed win 7 build 7100,and my onboard sound card is not working,my sound properties and volume control shows it is working but there is no sound coming out,ive checked the volume and all the stuff that is usually overlooked and ive checked my drivers and they are up to date,i have a really good sound blaster sound card,when i put it in sound works great,but there is a problem with it because it causes my pc to restart every 30 minutes or so,thats why im tryin to use the built in card,here is what i can tell you about my system:

Mainboard : Unspecified nVidia-nForce
Chipset : nVidia nForce2 400
Processor : AMD Athlon XP @ 2200 MHz
Physical Memory : 1536 MB
Video Card : NVIDIA GeForce 7800 GS (Microsoft Corporation - WDDM)
Hard Disk : WDC (80 GB)
DVD-Rom Drive : SONY DVD RW DW-U14A ATA Device
CD-Rom Drive : RW-241040 ATA Device
Monitor Type : Hewlett Packard HWP - 18 inches
Network Card : Nvidia Corp nForce MCP-T Networking Adapter
Operating System : Windows 7 Ultimate Professional 6.01.7100
DirectX : Version 10.00
Device Audio : nForce MCP-T Audio Codec Interface

if anyone can help i would be grateful,thanks

Try changing the jacks? A lot of computers have a jack in front of it and also behind it. Did you try both?

this computer only has the jacks in back,the pink,blue and green,i have tried them all,in the sound settings there is a page where you can select to change the "line in" to rear output and change the "mic in" to center output,i put a check in these boxes once and moved the jacks around,i did get sound from the line in,though it wasnt that good cause it was rear only,but now if i do that i get nothing.

Hello to all

I've got excacly the same problem,
My MO/BO has onboard the Realtek AC97 and when I use Windows 7 I've got NO SOUND at all

I have download the latest drivers from Realtek which there are for Windows 7 but still Nothink!! I've got NO sound!
But When I use a program ex. Winamp it Looks like all works fine!
Even inside the propertes of realtek Sound manager it shows that the the Pin hasPlugin correctly to Line Out.

Does anyone has Solucion for This one?? (except for buying a new Sound card)

Open the sound mixer and make sure that you have speakers selected as your main playback device... for some reason, the default setting is headphones...Good Luck..

It is the Default Playback Device....It Was couse now I'm Unstall the Driver and trying to install it Again...

Lets see Whats Will Happen...

Still Nothink.... Still Doesn't Work...

Onyone??

Fix it,
I Change the outout to the Pink (the Microphone in put) and change it to Output and works Fine.