You can't just access any machine on your network and create files or directories, and more than the you can access my home without my permission and rearrange the furniture.
To move the chairs in my house you need the key to my front (or back) door - without that you aren't getting in!
With a remote PC, it's the same: unless you can log into the remote PC with a valid username and password combination, you can't affect the hard drive content. And for a path like that, you need to be an admin on the remote PC as changing the root folder of a boot drive is frowned upon these days for security reasons.
Normally, you would give the name of a shared folder on the remote machine in order to access it, or you aren't getting in anyway - and sharing the root is a dangerous thing, so don't expect too many people to do it!
And you probably want to use the
ConnectionOptions class[
^] to provide the login details for the remote machine.