Hi Mel, :wave:
Please go into the Device Manager > View > Show Hidden devices > tell us if there are any Yellow Exclamation (!) Marks or Red Crosses next to anything in the list, especially in the Sound, Video Game Controllers section.
If there are, post back (with a screenshot if possible) with what they are. If there are no adverse marks, well and good.
To get into the Device Manager > Right click the desktop icon Computer > Properties > in the left panel click Device Manager.
From the 'Speccy' list it looks as though you are using the on-board sound and no third party soundcard; is this correct?
Which Sound Drivers did you install with this machine, were they the ones from the motherboard CD/DVD, or did you download them from another source?
Have you checked the sound connection sockets to the motherboard to make sure that they are intact and not loose?
Post back with this information.
Kind Regards,