Sound card suddenly stopped working?

[General_Chris]

ok guys i have a strange problem

2 hours ago my sound card worked fine and now windows 7 tells me i do have sound nothings muted or something tryed different music players also restarted my comp reinstalled drivers but nothing comes through my Z-5500s everythings connected properly also it just wont play sound you guys know why this happens

thanks

 

[KING_OF_SAND]

Did you here any strange pops or hissing before all this happened?