File Based Write Filter

The File Based Write Filter (FBWF) component redirects all write requests directed at protected volumes to the overlay cache, which records and displays the changes while preserving the protected status of the target volume.


There are no services associated with this component.

Associated Components

No other components interact with this component.


The following table describes the configurable settings for this component.

Enable FBWFCheck to enable.
Cache TypeSelect Dynamic, Dynamic Compressed, or Pre-allocated. Dynamic is the default.
Maximum Cache Size in MBSpecify overlay cache size; defaults to 64 MB. FBWF overlay cache is limited to a maximum size of 1GB.
Disable page-file supportCheck to disable the creation of a page file.
Disable System RestoreCheck to disable system restore.
Disable Background Disk DefragmentationCheck to disable background disk defragmentation.

Note that if another component hs the two registry keys within it that this option is attempting to disable, then checking this option might have no effect if that component is built after FBWF. Components that are known to share registry keys with FBWF and could potentially disable this option include: Background Disk Defragmentation Disable, Enhanced Write Filter, and Disk Defragmenter. For more details please see Disabling Disk Defragmentation in Windows XP Embedded Help.

Disable Low Disk Warning NotificationCheck to disable low disk warning.
Number of protected volumesEnter the number of volumes to protect. Each volume is configured in turn by clicking on the Prev and Next buttons.
Protected Volume #Displays the current volume number.
VolumeDisplays the drive letter of the current volume to be protected.
Write-Through Files and FoldersList those files and folders for Selective Write Through, separated by newlines. Note that the full paths should not contain the drive letter or environment variables. There is no mechanism to detect possible inconsistencies between the resolved value and the drive letter.

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