root directory

In content for developers, use root directory, not home directory, to refer to the directory or folder from which all other directories or folders branch. In Windows, the root directory is indicated by a backslash (\). Don’t shorten to root when you mean the directory.

In other content, use top-level folder.

Example
Change to the root directory, and enter the following command: edit autoexec.bat

See also top-level folder