I assume it says "No supported compiler or SDK was found." when you run "mex -setup" in the MATLAB command window.
When installing the MinGW compiler, the environment variable MW_MINGW64_LOC is set with the path the MinGW installation folder. If this environment variable isn't staying set following the installation or after restarting MATLAB, the behavior described above may occur.This could be due to limited privileges.
Running the following command will display whether the MW_MINGW64_LOC environment variable is set:
The solution is to have an administrator set the variable.