Let me take a moment and point out, unless your using hardware from < 2005 or so, or one of the rare devices running a custom firmware you literally are using U

Let me take a moment and point out, unless your using hardware from < 2005 or so, or one of the rare devices running a custom firmware you literally are using UEFI when you think your booting in BIOS mode. Others have pointed out that the CSM is no longer being shipped. The CSM is the "Compatibility Support Module" and its a UEFI shim driver that adds the legacy bios INTx operations to a UEFI implementation. So, most people booting in BIOS mode on hardware built in the past 15 years or so are actually running UEFI with an extra shim.