I am using Windows Vista HOME Premium 64 bit.
i am using a realtek sound card.
I plug in my HEADPHONES before i turn on my computer
then i turn on my computer and when its done sstarting up i hear the sound of Skype logging in
so i assume the sound is working.
BUT WAIT THERES MORE!!!
Then i go play a song on Windows Media Player and NO SOUND.
Aftr that i go watch a video on Youtube and NO SOUND
Also, i start up one of my GAMES and NO SOUND.

So i go o COntrol Panel>HardWare and Sound>Sound
and i double click the Selection "Headphones"
After that I click the tab that SAYS Advanced.
And i press the "Test" button.
And then I HEAR A SOUND!!

So thats so weird cuz the sound doesnt work but yet it works.
BtW i dont have any programs muted in my Sound Options.
WHen i use my speakers instead of the headphones, all sounds works.
my headphones arent broken!

PLZ help I need to use my computer early in the mornign sometimes but I dont wanna wake anybody UP!!!Have you tried different headphones?oh i just edited the post
i havent tryed different headphones but i
tryed my headphones on a different device and it works.I would try different headphones before we look elsewhere. Let's rule out that possibility first.i tryed an EARPHONES but it didnt work eitherDid it ever work? Have you tried System Restore?