Hi, I have been searching all over the place to find a layman's solution to stop this annoying system interrupt problem. Your solution seems the right approach and therefore I have (a) downloaded Web installer, selected Win32 Development Tools and installed them; (B) Ran wpt_x86.msi; © however, on running xperf –on latency, I got following error: "xperf: error: NT Kernel Logger: Access is denied. <0x5>". I don't know how to proceed. I admit, I am only a normal PC user without any specific expertise in hardware/ software/ programs and I would appreciate if you would please elaborate how to get over the obstacles. Thank you for your time and help. VDev