Write filter
Windows write filters are tools specially developed by Microsoft Windows to protect a partition against write accesses. The write accesses are redirected to the RAM and the partition is secured in a preconfigured state as a result.
Filter | Windows Embedded Compact 7, CE6 | Windows Embedded Standard 2009 | Windows Embedded Standard 7 P | Windows 10 IoT |
|---|---|---|---|---|
EWF | - | X | X | - |
FBWF | - | X | X | - |
UWF | - | - | - | X |
Microsoft offers three write filters in the embedded sector. These write filters are the EWF (Enhanced Write Filter), the FBWF (File Based Write Filter) and the UWF (Unified Write Filter). These write filters pursue different concepts and differ from one another as follows:
- The EWF (Enhanced Write Filter) protects a partition at sector level. No exceptions.
- The FBWF (File Based Write Filter) protects a partition at file level. Exceptions are possible.
- The UWF (Unified Write Filter) protects a partition at file level. Exceptions are possible.
Write filters are not necessary with Windows CE, as the CE operating system runs entirely from the main memory.
Registry filter
In addition there is the Registry filter, which allows data to be shifted into the registry despite the write filter being activated. This function is supported only by the EWF and the FBWF.