HP 6720t - Mobile Thin Client Reference Manual page 22

NOTE: Because the ewfmgr.exe utility and the EWF status utility execute separate code, status
changes by ewfmgr.exe are not automatically reflected by the EWF status icon.
If you modify the EWF using the command line, you must right-click the icon (you can then click anywhere
on the screen to close the context menu) to refresh the status icon display. The status icon display is
refreshed automatically when you make modifications through the EWF utility. The EWF utility always
reflects the current status.
12 Chapter 2 Enhanced Write Filter (EWF)