YAML does not handle \ very well as it is an escaping character in most situations. When defining tasks I would highly recommend using the YAML for instead of the older key=arg form as it makes your code more readable and you don’t have to escape . Your task would now look like this
name: Copies file to Windows
win_copy:
src: /ansible/ansible.cfg
dest: C:\Users\YRunner\Desktop\test1
When using the YAML form, you don’t need to escape \ unless you have double quoted the value. I found you don’t need to quote a value unless you want to convert it to a string or it contains a :.
What I gave you is just the task to use in place of your win_copy one. You still need to specify the other playbook directives like hosts, tasks, roles and the like.