headphone troubleshooting

[teh_hunterer]

my computer wont detect my headphones, and therefore i can't use them. i've tried putting them in both the front and back speaker slots. I've also put my headphones into a stereo to test if they work, and they work just fine. why wont they work in my comp?

also: my sound is onboard

 

[teh_hunterer]

update: when i put speakers in, it just buzzes