Going to take the big plunge with a new case & power supply, new ASUS mobo, new P4, new RAM. Going to use the existing HDs, DVD burner, and PC cards from my existing unit. I have installed 1 mobo, but much simpler one than this one, and was quite some time ago. My new one is an ASUS P4C800-E Del, w/a 2.8 P4 Northwood & 1G of Samsung ram off the compatible list. I've got the manual and have been studying it. I don't anticipate problems with the physical install. Main Q is should I start it up and configure the mobo before I hook up my HD? I am going to back up the entire HD onto another drive before I install it. I'm also going to upgrade from SE to XP Home to take advantage of the hyperthreading. When would be the best time to do that? Before I take the HD out of the old unit, or after I get the new one all up and running incl the HD? Thanks for any tips!