I can't give you a step by step guide unfortunately but I would stay away from ACHI at first, searching around the net seems to bring up loads of issues with enabling ACHI mode.
My P5K-E will be here tomorrow and I am going to install windows with Sata set to IDE mode and see how I go from there.
Yes it will be as fast, don't worry!but will it still be as fast? I chose a SATA drive to run as SATA, otherwise i would have saved £10 and got IDE
Is anybody using a ide dvd drive with any of their P5K series? I have a ide dvd rom drive and a ide dvd burner at the moment and have a P5K-E coming tomorrow. I was reading in the other guys thread and apparently their is issues with only sata dvd drives working