this is really strange. the HDAudio, the directX and the USBport drivers cause the issues: Interrupt Info -------------------------- CPU Usage Summing By Module For the Whole Trace CPU Usage from 0 us to 33500000 us:      CPU 0 Usage,      CPU 1 Usage,       usec      %,      usec      %, Module   5470720  16.33,         0   0.00, HDAudBus.sys   5824632  17.39,         0   0.00, USBPORT.SYS   3921832  11.71,         0   0.00, dxgkrnl.sys you use several other USB devices (Generic USB MS/CF/SM/SD Reader USB Device). Can you disable them and check it again? Also does it happen when you disable AVG? the IDSFilter.Sys driver calls some USB functions. Also do you use the latest drivers for your graphic card ( Intel® 82945G Express Chipset)?