Windows

Assuming that you encrypted your files with Microsoft's Encrypting File Certificates, you may be able to recover the EFS Recovery Agent Certificate this way:

1. Open IE.
2. Click Tools.
3. Click Internet Options.
4. Click Content.
5. Click Certificates.
6. In the tabbed folders at the top, check the Personal Certificates and Trusted Root Certification Authorities for the certificate which states it is for EFS Recovery Agent.
7. Highlight the certificate and click Export.
8. Click Next.
9. Click Yes to Export the private Key.
10. Click Include all certificates in certification path if possible.
11. Click name the file and choose a location for the file.

If you have a backup of the FIRST domain controller in the domain, you can restore it and recover the certificate using the steps listed at:

http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/Default.asp?url=/resources/documentation/windows/xp/all/reskit/en-us/prnb_efs_uizt.asp