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: 
I think it's because docker thinks `c` is container name. You can use relative path rather than absolute path.

So if you are in `C:/` you can just:

```
docker cp my_container:/folder anotherfolder

```

Also notice that there are few differences between running commands in window's `cmd` and in `git bash`.

**1. You are using git bash:**

Or escape in `git bash` console on windows:

```
WlaDo@DESKTOP-RBBRJOD MINGW64 ~
$ docker cp eb19fc21889c:/data c:\test
copying between containers is not supported <--- we got this error which points to implementation for which I added link below

WlaDo@DESKTOP-RBBRJOD MINGW64 ~
$ docker cp eb19fc21889c:/data c:\\test
<--- no errors here -->

WlaDo@DESKTOP-RBBRJOD MINGW64 ~
$ ls c:\\test
<--- data from container -->

```

**2. You are using windows `cmd`**

From windows `cmd` the approach you have should work:

```
C:\Users\WlaDo>docker cp eb19fc21889c:/data c:\test
<--- no errors here -->

C:\Users\WlaDo> dir  c:\test
<--- data from container -->

```

Copying between containers [is not implemented](https://github.com/docker/cli/blob/master/cli/command/container/cp.go#L100) and throws the error.

For more info check documentation about [docker cp](https://docs.docker.com/engine/reference/commandline/cp/#extended-description)

> 
> A colon (:) is used as a delimiter between CONTAINER and its path. You
>  can also use : when specifying paths to a SRC\_PATH or DEST\_PATH on a
>  local machine, for example file:name.txt. If you use a : in a local
>  machine path, you must be explicit with a relative or absolute path,
>  for example:
> 
> 
> `/path/to/file:name.txt` or `./file:name.txt`
> 
> 
>
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"`