I installed theano but when I try to use it I got this error:

WARNING (theano.configdefaults): g++ not detected! Theano will be unable to execute 
   optimized C-implementations (for both CPU and GPU) and will default to Python 
   implementations. Performance will be severely degraded.

I installed g++, and put the correct path in the environment variables, so it is like theano does not detect it.
Does anyone know how to solve the problem or which may be the cause?
On Windows, you need to install mingw to support g++. Usually, it is advisable to use Anaconda distribution to install Python. Theano works with Python3.4 or older versions. You can use conda install command to install mingw.
theano g++ not detected