So I recently reformatted my computer with Vista Home Premium.
There's a problem though. When i stick my headphones into my laptop or my speakers, it doesn't work. I turn on my iTunes and any other music player, and the music doesn't play out of my headphones or speakers, it comes out of the laptop speakers instead!
When I try to go to the preferences menu or settings menu for the headset/headphones, and I hit the "test" button, the sound comes out of the headphones.

So the audio jack is working...but only when I force it to with the test button.

Any help here guys? I really hope that I don't have to re-reformat my computer. I have to DJ a gig soon and need my laptop!
Thanks in advance!

erm...i set my DIGITAL OUTPUT DEVICE (SPDIF) Set Default, and the headphone symbol and Speaker symbol disappeared from the list.
Now i have no sound coming anywhere! Whaaat?

I downloaded the Realtek software for my computer from the Acer website! Thanks ScottW and JKay!
I got this sorted. Kinda a silly problem but i guess i wigged out a little! hah!

Thanks!