Once every ninety days, I always find someone who needs help fixing audio volume issues. Because of the frequency of this issue, I can usually find the issue within five minutes and resolve in ten minutes.
1. Look to see if the mute notification is located on the Taskbar. If the mute notification is missing, check to see if the volume is too low to be heard then increase it to 50% or more.
2. Check around the computer for external speakers. These are often at the side but may be mounted to the back of the monitor. If the computer does has external speakers, make sure that it is powered up via USB or an adapter (a red, green or blue light on the speakers should indicate this) and that all the audio cables are undamaged and plugged in correctly into each other and the sound card in the rear of the computer. To lock or unlock Dell speakers from a monitor, see the instructions.
3. Check the volume percentage for each program (YouTube, Windows Media Player, VLC, etc) that creates audio as the setting can be off or ver low which is why the main volume has no effect.
4. Check to see if the (audio) drivers are installed and were installed correctly. If the device never had sound, then you may have the wrong drivers. If it had sound before, the drivers are possibly corrupted and needs to be removed and reinstalled. Before attempting this, try and save your files and then restart the computer. 60% of the time, a hiccup makes it appear the drivers are corrupted.
5. Save any necessary data then unplug, if any, external speakers while the audio should be playing. The will let you know if the speakers are damaged as the internal speakers should start working. If there are not external speakers, power off the computer so that you can check to see if there is an internal speaker located inside the computer and if the speaker is securely attached to the motherboard or if the leads/cable is damaged. Note that some computers do not have internal speakers and with will have to use external speakers or headphones.
6. Audio can be disabled in the BIOS as well for internal speakers and is usually done by an IT Department for public settings such as classrooms and libraries to limit disturbance to other users or to prevent you from listening to movies and music all day instead of the task at hand. Be aware the BIOS may ask for a password to make any changes. Although the internal speakers are disabled, the headphones should still work and Bluetooth if it slipped their mind.