hi everyone, this is my first post since joining and I have high hopes that someone can help. provided that my external drive is running before i boot it is recognised and is useable, but if i switch it on after booting then it is not recognised. i understand that this procedure is similar to 'hot swapping' with a usb connection and for this to work with a SATA drive 'AHCI' has to be enabled in the bios setup. my bios has four settings available - native ide which is the default setting that i normally use, raid, legacy ide and ide-ahci. i set it to the last option which would appear to be the one i need and the only difference that it made was to increase the boot time from a normal 1 minute to in excess of 5 minutes. i tried all the other settings in turn and none of them did what i want, which is to be able to switch the drive 'on' and 'off' as i need it. i also found in another forum that 'msahci' driver should be loaded at boot time ( it is normally not by default) microsoft KB922976 refers. the bios file and the motherboard drivers are up to date. so can anyone see anything that i have missed or perhaps it is not possible.