Windows Embedded Standard provides two write filters: FBWF, which operates at the file level, and Enhanced Write Filter (EWF), which operates at the sector level.

In most cases, you use FBWF; however, to support NTFS fully, you must use EWF.

EWF supports the following NTFS features that are not supported in FBWF:

• File locking and unlocking
  
• File ID in NTFS
  
• Reparse points
  
• Quota
  
• Hard links
  
• Opportunistic lock
  
• File compression and encryption
  

In addition, to use Hibernate Once Resume Many (HORM) you must choose EWF.

EWF also provides the following functions that are not providded in FBWF:

• Support for multiple overlays
  
• Support for disk overlays
  
• Live commit and disable
  

To use EWF and FWBF together in the same OS image, enable EWF on one volume and FBWF on another volume.

Note:
The Windows Embedded Standard installer installs all files relating to EWF and FBWF in the EWFAPI directory and FBWFAPI directory at %Program Files%\Windows Embedded.