I believe many of those interested in studying DL heard of this course:
https://www.udacity.com/course/deep-learning--ud730
I am taking the course now and would like to share step-by-step instruction on how to setup learning environment on Windows from scratch.
The first answer named SETTING UP THE ENVIRONMENT is about setting up the learning environment. You run it only once.
The second answer named AFTER LOCAL MACHINE REBOOT is about how to start the environment over after you reboot your computer.
See the third answer named HOW IT ALL WORKS to learn how all that stuff works (or you can follow the first answer blindly and check it out later).