1. Setting a username The first thing you should do is set the username Mercurial will use for commits. It's best to configure a proper email address in ~/.hgrc 1 (or on a Windows system in %USERPROFILE%\Mercurial.ini) by creating it and adding lines like the following: [ui] username = John Doe <john@example.com> 2. Working on an existing Mercurial project If you have a URL to a browsable project