Manually Edit the TortoiseHg Registry

 Sometimes you have spurious entries that cannot be removed from the UI.

You can manually edit the Repository Registry by going to the local configuration directory--something like: C:\Users\username\AppData\Roaming\TortoiseHg--and editing the file:

thg-reporegistry.xml

If you have an empty group, there will be a line like:

    <allgroup name="default"/>

which you can just delete.