I don't have the duplicates removed, but this should help get you on the right track:

DECLARE @ModuleId INT, @FriendlyName NVARCHAR(128), @Count INT;

DECLARE [cModules] CURSOR FOR 
SELECT v.[ModuleId],v.[FriendlyName] 
FROM [dbo].[vw_Modules] v 
WHERE v.[IsAdmin] = 0;

OPEN [cModules];

FETCH NEXT FROM [cModules] INTO @ModuleId, @FriendlyName;

WHILE @@FETCH_STATUS = 0
BEGIN

 SELECT @Count = COUNT(tm.[TabModuleID]) FROM [dbo].[TabModules] tm WHERE tm.[ModuleId] = @ModuleId;

 PRINT N' The "' + @FriendlyName + N'" Module is used ' + CAST(@Count AS NVARCHAR(50)) + N' time(s).';

 FETCH NEXT FROM [cModules] INTO @ModuleId, @FriendlyName;
END

CLOSE [cModules];
DEALLOCATE [cModules];

This is from a previous thread along the same subject: http://www.dotnetnuke.com/Community/Forums/tabid/795/forumid/118/threadid/190029/scope/posts/threadpage/2/Default.aspx

Here is the SQL SELECT statements we use to report portal module use and non-use. I hope this helps.

This SQL statement returns the pages in all portals which my installed modules are being used on:
SELECT     TOP 100 PERCENT dbo.DesktopModules.DesktopModuleID, dbo.DesktopModules.FriendlyName, dbo.ModuleDefinitions.ModuleDefID,
                      dbo.Modules.ModuleID, dbo.Modules.ModuleTitle, dbo.Modules.AllTabs, dbo.Modules.PortalID, dbo.Tabs.ParentId, dbo.Tabs.TabID,
                      dbo.Tabs.TabName, dbo.Tabs.Title
FROM         dbo.TabModules INNER JOIN
                      dbo.Modules ON dbo.TabModules.ModuleID = dbo.Modules.ModuleID INNER JOIN
                      dbo.Tabs ON dbo.TabModules.TabID = dbo.Tabs.TabID INNER JOIN
                      dbo.ModuleDefinitions ON dbo.Modules.ModuleDefID = dbo.ModuleDefinitions.ModuleDefID INNER JOIN
                      dbo.DesktopModules ON dbo.ModuleDefinitions.DesktopModuleID = dbo.DesktopModules.DesktopModuleID
WHERE (dbo.DesktopModules.FriendlyName = 'Reports')
ORDER BY dbo.DesktopModules.DesktopModuleID, dbo.Tabs.TabName

Results (you can omit the WHERE clause)

This SQL statement returns which installed modules are NOT being used:
SELECT     TOP 100 PERCENT dbo.DesktopModules.DesktopModuleID, dbo.DesktopModules.FriendlyName, dbo.DesktopModules.Version,
                      dbo.DesktopModules.IsPremium
FROM         dbo.Modules INNER JOIN
                      dbo.TabModules ON dbo.Modules.ModuleID = dbo.TabModules.ModuleID INNER JOIN
                      dbo.ModuleDefinitions ON dbo.Modules.ModuleDefID = dbo.ModuleDefinitions.ModuleDefID RIGHT OUTER JOIN
                      dbo.DesktopModules ON dbo.ModuleDefinitions.DesktopModuleID = dbo.DesktopModules.DesktopModuleID
WHERE     (dbo.DesktopModules.IsAdmin = 0)
GROUP BY dbo.DesktopModules.DesktopModuleID, dbo.DesktopModules.FriendlyName, dbo.DesktopModules.Version, dbo.DesktopModules.IsPremium
HAVING      (COUNT(dbo.TabModules.TabID) = 0)
ORDER BY dbo.DesktopModules.FriendlyName

Results