Vista - no sound

yesterday I had sound on my dell Inspiron. Today I have no sound and the small icon on the tool bar has disappeared. A look at sound on the control panel leaves me baffled. help please
Ian

What does the baffling bit look like?

To help us help you we will need much more information.

can you please be a bit more descriptive about the issue. That what happens when you check the sound in control panel.

I see these two options:
Speakers/Headphones
Sigmatel high definition audio CODEC
working.

I see these two options:
Speakers/Headphones
Sigmatel high definition audio CODEC
working. There is a small green circle with a tick inside it.

Digitil Output Device (SPDIF Out)
Sigmatel high definition audio CODEC
working. There is no small green circle with tick

If I highlight the second one and click set default button the small green circle moves to the second option. I can move it back to the first the same way.
If I click on the properties button it takes me to setting levels, custom, enhancements etc. there are no external speakers, only those in the laptop.
I can change the level on speakers but it makes no difference to the sound. I cna also change it on PC speaker but only from zero Db at top to a negative number. nothing I do makes any difference to the sound output. Do you need any more info?

well, check if the speaker stick the PC or not through control panel. and the sound volume is in speaker mode yet? if its still that, need to find technical support from customer service

Hi Ian, Welcome to the Forum.

Speakers is the right device, it should be set to default. When Speakers is highlighted you should be able to configure your setup using the configure button.
You could try right clicking on the Digital device and select Disable.

If this doesnt get your sound back go to Device Manager double click on Sound, video and game controllers, right click on the Sigmatel entry click on properties, click on the Driver details tab and click on Roll Back Driver.

I hope this helps

Pooch