Unable to open previously encrypted folder after reloading system

Q: Under Windows XP system, using the system's own encryption features to encrypt some files, after reinstalling the system, open these files prompted "Access Denied", but the current user has full control of the permissions ah.

A: If you use an EFS encrypted file, reinstalling the system when you back up the certificate or set up the recovery agent will result in the inability to decrypt the file, resulting in a permanent loss of data. So far, there's no good solution. However, if you use a ghost type of tool to back up the partition where Windows XP resides after encrypting the file, you can restore the backup to decrypt it. Therefore, it is very necessary to back up the certificate in time, the specific method is: Open Internet Explorer, select the Tools menu → Internet options → content, click the Certificate button, select the "Personal" tab, you may display multiple certificates in the list. Select the certificate that displays the Encrypting File system in the intended purpose of the certificate, and export the certificate by clicking the Export button. Next, click Next in the Certificate Export Wizard, select Yes, export the private key, and then click the Next button two consecutive times. When you enter a secret that you want to protect your private key, click Next. Enter the path to save the certificate and private key in file name, and then click next → finish. After reinstalling the system, you need to import the certificate and private key. The import method is simple, click the Import button in the dialog box in Figure 14, locate the certificate and private key, and enter the password.