hi, I am new at this,I have no sound from my computer,can someone help ?

hi, my computer had sound through pluged in speakers, but at night my two kittens were jumping on my key board, when I woke a couple of times my computer was froze, all sudden I have no sound,but when I click on the speaker down on the right hand corner it shows volume, but now it has 2 enternet explorers on it a long with my speakers, it once said it was missing a driver, please help me get back my sound, when I plug in the extra speakers I can hear the speaker but no sound from the computer.so exhausted please help me..