Thanks for help chaps Mobo is an Intel Bad Axe 975X (LGA775) Dual DDR2 PCI-Express Motherboard Its only a month old and its fully updated as much as it can be right now. Maybe at some point an update will sort out the crackling. The guy at OCUK is sending me out a new SB sound card for free so hopefully this will cure it Ch33rs again for help :welcome: