hmmm... last summer when i got into xbox modding (dont go there, its not worth it), i told my friend how to read an xbox hd on his dad's pc. He did something wrong, and a similar occurance began. It was a dell dimension something, and whenever you turned it on, it would say something like "boot disc not found, press f1 to continue". If you pressed f1, it would work fine. But i couldnt get the message to go away. I dunno. Try setting the jumpers on the HD differently. But youve already tried 5 hd's... hmmm..... might try a bios reflash. or maybe the jumpers on the dvd drive are set to master, and the pc is looking to it first to boot from. make those are not set to master. If none of that works, then im at a loss. Try it and report back. Hope this helps!
Intel Conroe e6750
SLI EVGA 8800gts KO's
4GB Patriot DDR2 800mhz
22" Widescreen Sceptre LCD monitor 5ms
OCZ 700W psu
320gb seagate w/ perpindicular tech.
Creative SB X-Fi Fatality
Thermaltake Armor: Extreme Edition