Most of the time if you have sound on your computer one minute, then the next minute you don't, you can update your drivers. There are alot of various driver reasons why a sound card will go out on a computer, and it is best that you check each one, beginning with your windows update (if you're using a pc), then with your sound card manufacturers website, then with your motherboard, bios.. etc. The list of options is endless.

However, here is one tiny bit of advice which seems my first assumption to the reason was the correct one .. NEVER plug and unplug your speakers from your sound card (back of your computer) while you are actually playing something with sound. It can, and will, blow the sound card and you'll need to replace it. If you're using an onboard sound card (one that is built into your motherboard) there is no hope other than purchasing a removable sound card that will fit into either a pci, pci-e, or agp slot. Of course you'll need an empty slot in which to insert your new sound card in to. If none are available and you cannot do without something else that is occupying one of those slots, then there is only one other recourse... a new motherboard, or in today's market, a whole new computer.

So again, heed the advice and make sure that everything, meaning your computer, is 'off' before you start plugging in new speakers.

btw.. I just purchased a Diamond Xtreme 7.1/24 bit pci sound card.. it's great!

@kyo, that information is totally correct and agree all the way. sound cards are extremely picky and are constantly being updated and tend to have lots of problems... varying with the operating system and how you configure your settings...

XD Linux is a great operating system but the sound cards tend to malfunction and are needed to configure and fix constantly it was such a hassle in class