problem with sound

[airGraph]

hi , i have a problem with my headsets i bought a SH pc and when i connect with my headsets back the sounds doesnt work and i heard a whiz , the headsets work i connect on a laptop and work perfectly , i updated my drivers , i installed windows 8.1 i updated the latest version of bios , whats the problem ? i have a source noname 450w motherboard h61m-ds2
in right corner when i put some music on youtube looks like work

 

[popatim]

Try connecting into the back, perhaps the fronts are not hooked up or not correctly.

 

[airGraph]

Try connecting into the back, perhaps the fronts are not hooked up or not correctly.

i connected back , doesnt work when i connect its apper in realtek to select headphones i select and i head this whiz and no sound , when i select line in no whiz no sound