Install GCC ARM Embedded Toolchain - Willeby/GNU_ARM_Eclipse GitHub Wiki

Download pre-built GNU toolchain for ARM Cortex-M processors:
GNU ARM Embedded Toolchain

Do not change the recommended install path!
(C:\Program Files\GNU Tools ARM Embedded..)

Add C:\Program Files (x86)\GNU Tools ARM Embedded\6 2017-q2-update\bin to the system variables.

Test if the compiler is functional in the console with:
C:\arm-none-eabi-gcc --version