Microsoft Download Center Archive

Post Upgrade EFS Recovery Tool 1.0 (KB948690)

  • Published:
  • Version: 1.0
  • Category: Tool
  • Language: English

This tool can be used by server administrators to recover special user profiles and EFS encryption keys after a Windows file server has been upgraded to Windows Server 2008.

  • When a user encrypts a file stored on a Windows file server the actual encryption of the file occurs on the server. To accomplish this, a special profile is created on the server in order to create and store an EFS (Encrypting File System) encryption key on behalf of the user. Thereafter, each time the user accesses their encrypted files on the server, this special profile is loaded on behalf of the user, and the previously created encryption key is used.

    Issue: These special user profiles are not migrated when a Windows file server is upgraded to Windows Server 2008. When a user attempts to access their encrypted files, the upgraded file server does not see a special profile for that user and subsequently invokes the creation of a new special profile, with new EFS encryption keys. These new keys are now different than the original keys for the user, and therefore the decryption of previously encrypted files fails.


Status: Deleted

This download is no longer available on The downloads below are archives provided by the Internet Archive Wayback Machine from the Microsoft Download Center prior to August 2020.

FileSHA1 HashSize
EfsTool.msie6b5ecc5fa739bb5a8c7604ce5fda4baf295a8dc66 KB

System Requirements

Operating Systems: Windows Server 2008

  • Windows Server 2008

Installation Instructions

  • 1. Click the Download button on this page to start the download.

    2. Do one of the following:

    - To start the installation immediately, click Run.

    - To save the download to your computer for installation at a later time, click Save.

    - To cancel the installation, click Cancel.