People Search does not return any results

Follow the steps below to address the problem around People Search returning no results (even though you know that there are people in the database that match your search criteria):

1) Open Shared Services Administration
2) Click on Search Settings > Content Sources and crawl schedules > Manage Content Sources
3) Select the "Local Office SharePoint Server sites" content source
4) On the "Edit Content Source" screen, Update the Textbox for "Start Addresses" to include a new entry for the URL of your site collection name starting with "sps3://". For example, "sps3://intranet:80"
5) Select the checkbox "Start full crawl of this content source" and Click "Ok"
6) Wait till the indexing finishes. (You can check the status of indexing by accessing this area - "Shared Services Administration: SharedServices > Search Settings > Configure Search Settings"
7) Goto your site collection (for example http://intranet:80) and perform your people search to find results