Both myself, and Aaron Konstram are having problems with the complete shutdown of our machines. I am running FC5, and since some updates to FC5, kernels later than the original kernel installed from the CDROM refuse to shutdown cmpletely. The shutdown messages reach "power off" then nothing, and you have to press, and hold the start button on the PC to switch the machine off. When shutdown reaches the power off stage, I hear the harddrives spin down, but the machine is still active. these ar the kernels on my FC5: 2.6.15-1.2054_FC5 (this one shutsdown ok) but all of these refuse to shutdown completely: 2.6.17-1.2174_FC5 2.6.17-1.2187_FC5 2.6.18-1.2200_FC5 2.6.18-1.2239_FC5 and 2.6.18-1.2257_FC5 I have been googling, and found suggestions to use "lapic" . I'm not sure how to use it. I tried at the grub prompt for the kernel, using "lapic", or lapic=on" (without the double quotes) , but no success. Anyone have any suggestion how to use lapic, or even if this might solve the problem? Nigel. btw. Aarons having similar problems with FC6 not shutting down completely.