I can't get any sound from media player, games etc. I have checked all the sound mutes and volume levels. I have also checked in device manager and says that everything is working and enabled and there are no drivers missing. Thanks in advance.
If you go to control panel>sounds and audio devices and click the audio tab, try changing the Sound playback default device (although there may only be one option) if theres more than one try hearing audio using the other device.
Failing this, have you unplugged anything at back of PC recently? Try changing the speaker jack to different soundcard socket?
Check whether your speakers are working? Try plugging them into a stereo system for example.