Windows XP allows you to secure the data on your hard disk by taking advantage of the Encrypting File System (EFS). Only Windows XP Professional allows you to encrypt files using EFS; you don't get this feature with Windows XP Home. EFS allows you to encrypt files so that only your user account (or those you designate) can access the contents of a file. This is a useful feature if you keep sensitive information on your hard disk and don't want that information to fall into the wrong hands in the event that your computer is stolen. One problem with EFS is that if you lose your file encryption certificate, you won't be able to access the encrypted files and NO ONE will be able to get them for you (except for a Recovery Agent). To prevent this kind of disaster, you should back up your file encryption certificate. Here's how:

1. Click Start and then click the Run command.
2. In the Run dialog box, type mmc in the Open text box, and click OK.
3. In the Console1 window, click the File menu and then click the Add/Remove Snap-in command.
4. In the Add/Remove Snap-in dialog box, click the Add button.
5. In the Add Standalone Snap-in dialog box, select the Certificates snap-in and click the Add button. Then click the Close button in the Add Standalone Snap-in dialog box.
6. Click OK in the Add/Remove Snap-in dialog box.
7. In the left pane of the console, click on the "+" sign to the left of Certificates - Current User entry.
8. Now click the "+" sign to the left of the Personal entry.
9. Click on the Certificates node. You should see your user account name in the right pane of the console. Right click on your name, point to All Tasks and click on Export.
10. Click Next on the Welcome dialog box.
    On the Export Private Key page, select Yes, export the private key and then click Next.
11. On the Export File Format page, remove the checkmark from the Enable strong protection checkbox. The Personal Information Exchange option should be selected by default. Leave it that way. Click Next.
12. Enter a password that you will remember in the Password text box. Type the password again in the Confirm Password text box. Click Next.
13. On the File to Export page, type a:\efscert in the File name text box. Click Next.
14. On the last page of the Wizard, read the settings that were included and then click Finish.