A lot of good information was covered in this thread: http://windows7forums.com/windows-7-support/5028-windows-7-wont-shut-down-help.html but it still didn't solve my problem for my board (plus the original post was really old so opened a new topic) I have a MSI k9n2 Diamond motherboard with the latest BIOS (v2.4) but my system continues to run after a shutdown. The OS completely shuts down but the hardware (system fans, video card fans, lights, etc.) continue to run. If I kill the power switch and turn it back on the computer boots just fine. Also, the computer can restart properly - I only have problems shutting down.