Integral Speakers On Monitor Not Working

[dunnitall]

My PC Win 8.1 with "classic start" Win 7 and has an HP monitor. Up until a day ago the integral speakers worked on the screen, I don't have separate speakers attached. The icon for the speaker is on the task bar and all I had to do was click on it to turn the volume up. I normally keep it off until I wish to listen to something.

Now, the speaker icon has a little Red Cross on it and when I click on it says no speakers attached (or mic or sound recorder) which is correct. I have tried to correct this but with no effect, so can anyone please advise how I might restore this function to use the volume again? Many thanks for your help.

[Buenchico]

I suspect that you've got a corrupt sound driver.

Click the Start button.
Type 'device' into box.
Look for 'Device Manager' above it.
Click on it.
Double-click 'Sound, video and game controllers'
There you'll see the name of your sound card (if your PC has one installed) or something telling you that your computer has 'onboard sound'. (On my PC that entry reads 'SoundMAX Integrated Digital HD Audio').
Double-click on the relevant entry.
Click on the 'Driver' tab and then on 'Update Driver'
Click 'Search automatically . . . '

If the driver isn't found, cancel the operation and click on 'Driver Details' instead. Note down the manufacturer and driver version then try to locate it on the website of the manufacturer of the sound card (or motherboard if appropriate) or of the computer. Ask if you need help. If you download the driver installation file in that way, double-click on it to run it and then restart your computer.

[Buenchico]

PS:
BEFORE doing any of the above, have you tried simply turning your PC off and then on again? It might just be that the sound driver failed to load when Windows did.

PPS:
If the off-and-on trick doesn't work, an alternative approach (to the one on my first post) might be to try System Restore in order to take your PC's registry back by a few days. (Click Start. Type 'rest' into the box. Look for System Restore above it and click on it)

[dunnitall]

Thank you for that Chris, much appreciated. The problem started a few days ago so the PC has been on and off since then with no change. Don't suppose it's anything that could have happened whilst AVG anti virus thing has been playing up... I just wondered if that could have put glitch on things. Anyway I will have a look at what you've kindly given me but will be next week now. Once again many thanks.