If you want to delete a community folder, you must first delete all of its child folders and communities using the Communities tab in the Portal Administration. Once you’ve done this, to delete a community folder, use the ATG Control Center (ACC):
Start the ACC and open the Portals > Portal Repository window.
Display Items of type Community folder, then click List.
Select the parent folder of the folder you want to delete. Select its Child folders property and click the ... button.
Select the folder that you want to delete and click Remove.
Click OK. You are returned to the Portals > Portal Repository window.
Select the folder that you want to delete. Be sure that its Child folders property is empty. Right click on the folder you want to delete and select Delete from the menu. Click Yes in response to the Delete Confirmation prompt.