Ansible issue ERROR! the playbook: samplebook.yml could not be found

I am getting below error even though the file exists in the path.

ERROR! the playbook: samplebook.yml could not be found

I have used below command to run the playbook

ansible-playbook samplebook.yml

Update 1:

Actually below command is creating yml file as swp file

vi samplebook.yml

ls command returning only hello.txt file I'm not getting why .yml and .cfg fies not getting recognized.

swp files getting deleted once I close command window.

Am I creating yml files in wrong way?

kindly suggest how to create yml file or ansible playbook in windows 7 using Cygwin

Ansible is already installed.