ERROR: "A Required CD/DVD Drive Device Driver Is Missing"?

I have what appears to be a common problem with Win 7, as I've seen numerous users ask this question here & on other forums, but so far, none of the suggested fixes that I've found have worked for me. I'm trying to install the full retail version of Win 7 Home Premium on a new SATA hard drive in a new 64-bit PC. I'm doing this because the drive that came with the PC had Win 7 Pro on it, but it was a trial version and I don't have a key or disc for it. However, I have a new copy of Win 7 Home Premium, and since I can't downgrade without hacking the registry (which didn't work either, btw), I decided to get a new HD & start over with Win 7 HP.However, when I try to start the installation from the disc, after I click "Install Now", I get the error message "A required CD/DVD drive device driver is missing". I'm stuck there.

The Win 7 disc allows you to remove the installation disc at that point & put whatever CD/DVD you want in the drive to try and find the drivers you need, so I tried the disc that came with the motherboard, which is a FoxComm. I'm able to get into the motherboard's installation disc & select "x64" under "driver" & also under "floppy". When I select those files, I get a quick green moving horizontal band, like it's downloaded the driver. If I select any other folder or drive, I get the error message "No device drivers were found" otherwise, so I believe I'm on the right track.But still I get the same message when I put the Win 7 disc back in --- "A required CD/DVD drive device driver is missing". I also tried installing an ISO image and that didn't work.