So i had the same problem, with my dell model. I found out that i didn't have an audio thing downloaded onto my computer. If you have a
Dell computer, you can go to this link,
http://support.dell.com/support/down...atid=&im pid= Click on audio, and download one of the two they provide. ( i downloaded the second one)
after that, i just plug in my speakers and they work great

oh if that still doesn't work, try
start>control panel>administrative tools>component services>services>windows audio and make sure its started. if its on manual or disable, click
start device.
Hope i helped ! i had this problem for weeks and i couldn't stand it anymore
[size="2"]Credit: everyone who posted on this thread.[/SIZE]
if you have any other problems, feel free to email me @
xeverlasting@live.com