To find pages with installed module you can run this SQL code (just replace HTML with Friendly Name of required module):

SELECT *

FROM {databaseOwner}{objectQualifier}TabModules

WHERE   ModuleID IN

        (

        SELECT ModuleID

        FROM {databaseOwner}{objectQualifier}Modules

        WHERE   ModuleDefID IN

                (

                SELECT ModuleDefID

                FROM {databaseOwner}{objectQualifier}ModuleDefinitions

                WHERE   DesktopModuleID IN

                        (

                        SELECT DesktopModuleID

                        FROM {databaseOwner}{objectQualifier}DesktopModules

                        WHERE FriendlyName=N'HTML'

                        )

                )

        )