HP Laptop has no audio please help

I recently bought A laptop from amazon(elitebook 8440p) it came with a fresh installation of windows 7 home premiumx64 . I started updating all the old drivers and doing windows updates etc when all the sudden my audio wasnt working. The speaker symbol has the muted icon but when highlighted it says " no audio output device is installed " ive gone through the basic steps windows provides and nothing has fixed it . Under sound video and game controllers in device manager two devices are listed (IDT High Definition Audio CODEC) and ( Intel(R) Display Audio) both look normal and have no warnings and both are enabled

im slightly a noob and really want to use this laptop as the most ive done is update stuff and no audio isnt fun : (

Thanks in advance for any and all help :)