The system has built-in audio. It may just need to be configured to use the proper output device or load drivers.
In Control Panel/Sound make sure the proper default output device is selected. You may have 2 to choose from (HDMI and AC97 or HD). If you have speakers plugged into a green plug in the back of the system, then don't select the HDMI option.
If you have the computer connected to a monitor with a HDMI cable, then select HDMI and make sure the volume (on the monitor) is actually turned up.
You need to also check Control Panel/Device Manager to see if all drivers are installed properly. There will be indicators (if you have one, you'll know what I mean) that show if any device is having a problem.
Check these out and see if anything helps. Good luck!
Thank you..... I checked all above but to no avail, and now have inserted a sound card I have just bought from Map**** and it now works well.
Thank you once again and Happy New Year to you