How to enable API setting in Docker Tool box?

I have installed docker tool box in windows 8.1 machine. I want to enable docker API setting. I did below step to enable docker API setting. Docker is throwing below error message after updating below steps. Please help me how to fix this issues ?

Steps:-

Steps for enable Docker API :-

  1. Start “Docker Quickstart Terminal”. It starts Bash shell and is the place where all following commands will be run. Run docker-machine ip command and note the IP address of the docker host machine. Then do
  2. docker-machine ssh
  3. cd /var/lib/boot2docker
  4. sudo vi profile This starts “vi” editor in elevated privileges mode required for editing “profile” file, where Docker host settings are. (If as a Windows user you are not familiar with vi, here’s is super-basic crash course on it. When file is open in the vi, vi is not in editing mode. Press “i” to start edit mode. Now you can make changes. After you made all the changes, hit Esc and then ZZ to save changes and exit vi. If you need to exit vi without saving changes, after Escplease type :q! and hit Enter. “:” turns on vi’s command mode, and “q!” command means exit without saving. Detailed vi command info is here.)
  5. Using vi, change DOCKER_HOST to be DOCKER_HOST=’-H tcp://0.0.0.0:2375’, and set DOCKER_TLS=no. Save changes as described above.
  6. exit to leave SSH session.
  7. docker-machine restart

Error Message

An error occurred trying to connect: Get http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.24/containers/json
?all=1: open //./pipe/docker_engine: The system cannot find the file specified.

Docker Toolbox Info

Docker Tool box Info
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 8
Server Version: 1.12.3
Storage Driver: aufs
Root Dir: /mnt/sda1/var/lib/docker/aufs
Backing Filesystem: extfs
Dirs: 164
Dirperm1 Supported: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: null bridge host overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Security Options: seccomp
Kernel Version: 4.4.27-boot2docker
Operating System: Boot2Docker 1.12.3 (TCL 7.2); HEAD : 7fc7575 - Thu Oct 27 17:23:17 UTC 2016
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 995.8 MiB
Name: default