Acer Veriton N2620G - Manual (Page 13)

Understanding Your Thin Client | 13
All attacks on the terminal's security or unwanted changes can be
thwarted by simply rebooting the machine if the filter is turned on.
Operating the machine with the Filter turned off can be dangerous to the
terminal and the important OS files inside it.
Introduction to FBWF
The File-Based Write Filter, more commonly referred to as the FBWF, is
a an intelligent filtering system that allows you to protect specific volumes
of your local drive from write access, while simultaneously keeping less
important files like anti-virus databases or a user's Documents and
Settings folder persistent. The FBWF allows users to decide which
directories are persistent and which are transient. Persistent files are
files that are not protected by the FBWF filter, and all changes, good or
bad, will survive after rebooting. Transient files are files that are
protected by the FBWF filter and all changes that are made to these files
are neglected and forgotten upon rebooting the terminal.
How Does FBWF Work?
When the FBWF is enabled, it makes your files secure from that instance.
Rebooting the terminal will revert your system immediately back to the
state it was in when you enabled it, like a restore point. As long as your
FBWF is enabled, it is in a safe state. It stays safe because it writes all
changes made on the system on an overlay in the RAM memory cache.
An overlay can be thought of as a protective layer over the disk. All
changes made to the disk are written on the transparent layer instead of
the actual disk. When the terminal looks for information on the disk, all
upgrades and new installs can be found and accessed because it is
written on the overlay which is covering the disk.
However, once the terminal is rebooted, the memory cache is erased,
and the overlay is wiped clean, with no changes made. The system
automatically resumes from the same point it was at when you enabled
the filter.
To install new hardware and software, or to upgrade any existing
programs or applications on your system, you will have to disable the
FBWF. It is important to re-enable the File-Based Write Filter as soon as
the installation is complete so you can protect your terminal from
unnecessary disk writes. As long as you are not installing or upgrading,
it is necessary to leave the File-Based Write Filter in an enabled state for
correct performance. As long as it is enabled, your terminal is safe from
malicious network attacks or accidental uninstalls.