hi a little supplement from me - if the pc is booted you can check the boot-type via undocumented variable %FIRMWARE_TYPE% Typing echo %FIRMWARE_TYPE% in a cmd windows will return you legacy or not.
Doesn't work on anything less than Windows 8, I guess. Windows 7 doesn't create that Environment Variable, and the command fails.
Where does %firmware_type% come from? I've used it & know it returns UEFI or Legacy but it's not listed as an environment variable when you type "set". Never mind, my friend Google found that it's a: By the way this tool does not help the novice user know if they have booted in UEFI or Legacy, which is probably what they want to know...