Not to worry,
so did I and I had toi keep going back to re-read what had been written.
I am wondering, if the hdd is left unconnected, mount the CD ROM, change boot sequence to boot from CD (in BIOS), place windows Boot CD in ROM, Does the system boot?
Check that HDD's are set to "auto" in BIOS, or you could try for an auto search. Because apart from the illogical idea that the mobo interface is dead , it could be switched off. Also try putting the HDD on the other IDE. on its own!