How to connect this cable to motherboard, plz help

Hope this helps, never tried myself

http://www.hardwaresecrets.com/article/600/2

thanks was quite useful, shall reply after testing

thanks mate  

The pin header in your pic has one pin removed. That's the key to proper orientation of the associated connector. The cable that plugs in to the header should have a cooresponding pin position plugged so there's effectively only one way to plug the cable to the header. If the cable isn't plugged maybe there isn't a wire in the vacant pin position.