Ok, no prob's, we need to get some more info,
on desktop right click my computer,
click on properties,
click on device manager,
first, are there any yellow question marks ?,
on "sound, video and game controllers" click on the +,
what is listed there ?
next, go to control panel and open sound, you should see sonething like this,
What is listed there ?,
last of all we need to know the model of sound card you have, sigma tel make an awful lot of sound device's, so a model/type will help us find the correct driver.