Isn't the CMOS set to defaults to begin with? I didn't do this. I booted and entered BIOS first thing to get everything set up, then installed the OS. Once the OS was installed I booted into BIOS again just to re-check a few things (energy saving features, etc.).
falcon, start clean with the HD. Less headaches and you'll be glad you did. A new machine, a fresh start.
Regarding CMOS reset, I didn't do it on Mom's computer but did on mine. All I know is you should. Maybe someone who knows more than I can explain.