If you encrypt data on your computer, you need a way to recover that data in case something happens to the encryption key. If your encryption key is lost or damaged and you don't have a way to recover your data, the data is lost. You will also lose data if you store your encryption key on a smart card and the smart card is damaged or lost. To make sure you can always access your encrypted data, you should back up your encryption certificate and key. If more than one person uses your computer, or if you use a smart card to encrypt files, you should create a file recovery certificate. For more information, see Create a recovery certificate for encrypted files.
Open Certificate Manager by clicking the Start button , typing certmgr.msc into the Search box, and then pressing ENTER.
Click the arrow next to the Personal folder to expand it.
Click the certificate that lists Encrypting File System under Intended Purposes. (You might need to scroll to the right to see this.)
If there is more than one EFS certificate, you should back up all of them.
Click the Action menu, point to All Tasks, and then click Export.
In the Export wizard, click Next, click Yes, export the private key, and then click Next.
Click Personal Information Exchange, and then click Next.
Type the password you want to use, confirm it, and then click Next.
The export process will create a file to store the certificate.
Enter a name for the file and the location (include the whole path) or click Browse and navigate to the location, and then enter the file name.
Store the backup copy of your EFS certificate in a safe place.