F12 boot setup doesn't list C or CD/DVD drive

Hello,

On my Win 7 Gateway DX4320-01e running Windows 7 Ultimate 64-bit, I awoke this AM to an unbootable machine after a normal shutdown last night. Going to F12 to check my boot setup, I see that drives C: (my OS), my CD/DVD drive, and any of my USB ports are not listed, and, therefore unavailable for boot-up. I then went thru each F key separately at the BIOS window to see if anything happened- only F12 as explained worked at all. The delete key works (CMOS Setup Utility), but offers me nothing that will affect my boot situation.

I have an HP laptop which I am using now, but it has a 32-bit Win 7 OS, so I cannot use it to create a repair disc onto my SD card (one of the available boot options) The other available boot options are all my photo memory slots, and an external drive by Western Digital which stated when I bought it that it could not be used for booting. I'm hoping, though, that it might work for a repair disk, but I don't know how to create one using the 64-bit DVD and my external drive.

I have no idea what happened, and, although I have searched the internet for hours, I cannot find anyone else with this problem or any info on how to repair my situation. Can you offer me any advice? I am truly grateful for your time and expertise.

Grateful