Hi, does anyone know what could be causing this problem on my dads computer. He's running a 64bit windows 7. Every now and then , only for a second maybe a few more the sound will distort and sound kinda tinny. It happens every half hour or so in an irregular pattern. He has reinstalled windows and the problem has lessened (to the degree mentioned above). This just came out of the blue a week or two ago, it's never happened before and he has no new hardware in. Any help appreciated.