Install the iZotope Mastering Bundle to the default location.
Save the batch file located here to a location on your computer where you can easily find it (My Documents, the Desktop, etc).
Right-click the file and choose “Run As Administrator” from the shortcut menu.
You should see four confirmation dialog boxes informing you that the iZotope DLL files have been successfully registered.
The next time you start Sound Forge, the effects will be available in the Plug-in Chooser and FX Favorites menu (choose FX Favorites > Recreate by Plug-In Name to rebuild the favorites menu).