I have searched Google. I have used XP's help center. I have searched MSKB. EVERY time I shut down or reboot my computer (even software initiated), the system freezes on the "Windows is shutting down..." screen. Must manually shut down which, 9 times out of 10, requires the system to run scandisk at next boot. New system, AMD Athlon 64 3200, PCIe Nvidia video card, 160gb SATA main drive, 1GB DDR 3200/400, mobo is BioStar NF4ST-A9, usb keyboard and mouse, gblan, 19" LCD monitor with DVI connection, 450w PS. Not overclocked, not overheating, all drivers up to date, no conflicts, Win XP SP2 with all updates. Also, 90% of boots do not engage my mouse. Must unplug/plug to activate. Thanks in advance for any wisdom you can share. :-?