You must be on your SharePoint web server to install the webpart for farm or single server. This webpart will work with Portal and Services.

Run setup.exe

Now make sure the feature is activated by going to your SharePoint site and going to "Site Actions" / "Site Settings" / "Modify All Site Settings" / "Site Collection Features". If the feature Active Directory Tools is not activated, click the "Activate" button. Then it will appear in your list of webparts on any site in that site collection.