The Windows Embedded Standard 2009 May 2011 Feature Update adds two additional applications – "Enhanced Write Filter Management Tool" and "File Based Write Filter Management Tool" – which allow you to monitor the status and configure the filter drivers in your images.
The applications will start on system start and appear in the systray, also showing notifications when the overlay runs full. The tools can also be configured to deactivate automatic startup.
The new features can be downloaded from the Microsoft ECE: Windows Embedded Standard 2009 May 2011 Feature Update.
The two tools have a dependency on the Write Filter WMI Providers which were released in February 2011.