Features In Windows Embedded; Enhanced Write Filter (Ewf) - Advantech TPC-1581WP User Manual

3.1

Features in Windows Embedded

TPC product supports the embedded Windows platform. This section outlines the
important features (EWF, FBWF, UWF and HORM), that are provided in WES7/
WES8.
3.2

Enhanced Write Filter (EWF)

Enhanced Write Filter (EWF) and File-Based Write Filter (FBWF) redirect all writes
targeted at protected volumes to a RAM or disk cache, called an overlay. The overlay
stores changes made to the operating system, but is removed when the device is
restarted, restoring the device to its original state. Note that there is no disk-based
overlay support for Windows Embedded Standard 7.
EWF works at the sector level on protected disks and allows you to commit changes
so that they persist when the device is restarted. EWF is useful for thin clients that do
not need to store cached information or receive frequent updates. Changes made to
a system protected by EWF are stored in one or more layers that represent snap-
shots in time. Applying changes to an image applies all changes made to the operat-
ing system during a specific period of time.
Advantech provide utility to operate EWF. Refer below steps if you want to enable
1. Click Start Menu->All Programs->Advantech->AdvWF and click EWF Utility
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