No sound in old Laptop

Here's a question for you.

The computer I have at the moment is a fairly new laptop and to choose which microphone I want to use with it, I go to the usual place and right click the speaker icon on the bottom right hand corner of the taskbar for recording devices and choose from there.

The laptop I had before this one, the first time I ever got it before I ever bought a proper external microphone, I used the built-in array one which came, built-in the laptop itself. I believe this microphone is also used for all sound devices in the laptop. For example, if you were using Skype, you would need this device for other parties to hear you on their computer if you Skyped them.

Now bear with me. When I got this new laptop I gave the old one to my daughter. Now bear in mind I used to use the built-in array microphone in that one right at the beginning, before I ever bought a proper external one.

My daughter recently put Skype on the old one and we Skyped each other.

Now she could hear me fine but I could not hear her. I assumed that this was to do with the microphone settings in the old laptop where I used to use an old external microphone for speech recognition. I assumed it needed reconfiguring so that the built-in array microphone needed to be highlighted and set as default again.

So I right clicked on the speaker icon in the bottom right hand corner of the taskbar and then recording devices and expected to see the array microphone icon but there was absolutely nothing and everything in the box was grey. There was nothing there to choose from, absolutely nothing.

So my question is this. Can anybody tell me why this is happening and how I can correct the sound problem? Why is there absolutely no icon or anything showing at all? Surely I should have expected to see the built-in array microphone icon in the box but in the box, nothing at all was showing, not a bean.

Any ideas why this is? Any ideas how to put this right?

Thank you

andy t