Sometimes whenever I boot up my computer, I get this problem: svchost.exe - Application Error "The instruction at "0x7c91D5f8" referenced memory at "0x00000010". The memory could not be "read". And after that whenever I play something that has sound, it won't play it, or it won't play it without sound, or, it saids I have a "Bad Sound Driver". This problem occurs every once in a while, sometimes it happens and sometimes it doesn't. Does anybody know how to fix this???