Question: I'm trying to copy a file from a container to my host windows machine with this command

```
docker cp my_container:/folder c:\anotherfolder

```

the docker console returns

```
copying between containers is not supported

```

Why?

```
 Client:
 Version:      17.05.0-ce
 API version:  1.29
 Go version:   go1.7.5
 Git commit:   89658be
 Built:        Fri May  5 15:36:11 2017
 OS/Arch:      windows/amd64

Server:
 Version:      17.05.0-ce
 API version:  1.29 (minimum version 1.12)
 Go version:   go1.7.5
 Git commit:   89658be
 Built:        Thu May  4 21:43:09 2017
 OS/Arch:      linux/amd64
 Experimental: false

```

Answer: 
As the other answer stated, it's because it thinks the `c:` is a container name. You can solve this by wrapping the path in quotes like `docker cp my_container:/folder "c:\anotherfolder"`
A working path spec in mingw32 (git bash):

```
/$(pwd)/projects/acme

```

Note the `/` prefix!