Re: Sound gone on my computer
First grab a set of headphones and plug those into the appropriate socket and see if you get sound there.
If you do then the motherboard and sound system is fine and you've probably lost connection to the PC speakers. Could just be a cable loose inside.
If you don't get sound with headphones then your sound card/chip has probably got a problem with its drivers.
For that you would go into device manager, find the entry for your sound card/chip/device and look at the settings. There will be an option in there to reload the driver.
Failing that you can simply delete the entire entry for your sound card/chip in device manager. Then reboot and the system will automatically detect it again and reinstall it.