So you deleted your hidden recovery partition? Then you cannot use the recovery option in the BIOS anymore.
"C:" is not a physical drive, it is the name ("drive letter") of a file system of a partition on a drive. A proper operating system installer should first give you the option on which physical drive to install. Then you may even create a partition of your preferred size. This will get formatted and named "C" as default. Then the installation starts.
I don't know what's on your USB key, but maybe you need to prepare it newly from a proper CD image. You may also connect a disc drive via USB and install from a disc directly.