Docker Compose Up gives "The system cannot find the file specified." error
I just forgot to start "Docker for Windows" which resulted in that error.
You and I may or may not have the same problem. In the link posted by @Haken Lid above, the issue is with the PATH environment variable not having the correct version of Python.
BUT, for me, the issue was that I had not set all of my environment variables, by running
eval $(docker-machine env <vmname>)before I ran the docker-compose <any command>.
Run docker-compose with the Docker Quickstart Terminal. It will solve your error.
The Docker Quickstart Terminal is mostly a regular shell but allows to create a default machine. It can be used to connect to other machines as well:
eval $(docker-machine env <MACHINE_NAME>)