Certain advanced security features on Windows 10 work only on machines new enough to boot via the Unified Extensible Firmware Interface (UEFI). These include Secure Boot, Credential Guard, Device Guard, and the Early Launch Anti-malware driver. The wrong installation media or incorrect installation technique produces Windows 10 machines that boot from Legacy BIOS, not UEFI. This applies most often to BYOD laptop and notebook PCs where admins probably didn’t install the OS. What’s the quickest way to confirm or deny UEFI boot-up on Windows 10?
Above and beyond security features, UEFI also supports bigger disks, signed book loaders, plus faster bootup/shutdown/sleep/resume timing.
The Quick Way to Confirm/Deny UEFI Boot-up on Win10 PCs
Run the built-in Windows System Information utility (msinfo32.exe) to find the information you seek on the “BIOS Mode” line. If it reports BIOS, the machine runs Legacy BIOS. If it reports UEFI, the machine runs UEFI for boot-up. If BIOS shows up here, and you want to or security policy requires you to switch to a UEFI boot, a two-step process is needed. Warning: neither of those steps is terribly easy nor is it likely to be quick:
- You must check to see if the target device supports UEFI. The best way to do that is to find the maker’s product page and check for direct confirmation of UEFI support. If it’s absent, the device may not be able to support UEFI. Be sure to check third-party sites such as notebookreview.com, TenForums.com, and so forth to determine if the machine is UEFI-equipped or not.
- If you want a Windows 10 machine to boot from UEFI, there’s no way to switch from Legacy BIOS to UEFI except by a clean re-install of the OS (that’s because the low-level disk format has to be replaced, which usually involves a switch from MBR to GPT formatting and a complete disk wipe along that way). This means that capturing all settings, preferences, and data is a must, and that all applications will need to be reinstalled and reconfigured (and settings, preferences and data restored) following the re-installation of the OS.
Thanks to Shawn Brink at TenForums.com for putting an excellent tutorial together to explain how to determine UEFI boot-up presence or absence on Windows 10 PCs. This same information applies to (and was originally developed) for Windows 8 versions, BTW. One more thing: as Brink observes in that tutorial, the other conclusive method to determine the presence or absence of UEFI boot on a Windows 10 (or 8) PC is to open the Disk Management (diskmgmt.msc) utility. Then, look for the presence or absence something labeled “EFI System Partition” on the system’s Boot drive. If you see such an animal, the target machine can boot from UEFI.