As Tomas and Michael have suggested, you might have a look at your BIOS/UEFI setup in order to verify the boot order and to disable Secure Boot: disabling Fast Boot has nothing to do witrh Secure Boot and Debian cannot manage Secure Boot without special procedures
It is worth noting that the Debian Installer can be launched from inside Microsoft Windows: try to plug your stick in a USD port from your running Windows and then execute setup.exe (it is in the root folder of the stick). You could also directltly go to https://people.debian.org/~rmh/goodbye-microsoft/ to load the installer from internet. As simple as you can get... (cf https://en.wikipedia.org/wiki/Win32-loader)
