The hard drive format has nothing to do with getting into the bios. You can disconnect the hard drive from the computer and still power up and go into the BIOS, there just won't be any hard drive, and thus no operating system, to boot from. I don't think you're in full understanding of what the BIOS is, but that's ok.
If you downloaded digital river content, you would have to have a valid key in order to install, which would mean you would have had to have purchased one of those versions or that your computer came with one of those versions, but then had it removed. You can't just use one of those without a license key.
Aside from that though, that wouldn't cause the disk to not be recognized so either you've burned your ISO to a disc type that your optical drive doesn't support, or burned the ISO incorrectly, not making it bootable.