Windows 7: No audio output is installed

I have this new cursed laptop with win 7. Initially I could not get the internal mic to work with skype to I reinstalled the drivers from Realtek. When I go into device manager it all looks ok but I still have the speaker with red cross over it. I have tried all sort of things (hrs and hrs) recommeded on this site but nothing has worked. Please please help me!

I have attached a printscreen of the error messege it comes up with when I double click the speaker icon.




My laptop is an acer apire 5740
3 GB Memory
320GB HDD
intel core i5 processor 430m (2.26GHz, 1066 MHz FSB)
intel graphics media accelerator HD



[IMG]file:///C:/Users/Tesco/AppData/Local/Temp/moz-screenshot-4.png[/IMG]
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[IMG]file:///C:/Users/Tesco/AppData/Local/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/Users/Tesco/AppData/Local/Temp/moz-screenshot-1.png[/IMG][IMG]file:///C:/Users/Tesco/AppData/Local/Temp/moz-screenshot-2.png[/IMG]