VSdocman is used within MS Visual Studio .NET IDE as an add-in. You can load it (if it is not yet) as all other add-ins:
- go to Add-Ins menu
- then click Add-In Manager ...
- select VSdocman item and run it.
It is a good idea to set it to load on startup. After that new VSdocman item appears in Add-Ins menu as well as in standard toolbar.