If there’s NTFS partition on your hard disk, and the data on the partition has been encrypted, then you should make a backup key by any chance. And here’s the way to make a key:
 Click “Start--Run” command, and on the opened run dialog, type “certmgr.msc” and press Enter to open certificate manager. And under the branch “Current user—Individual--Certificate”, we can see there’s a certificate after your user name (if you haven’t encrypted any data on NTFS partition, then here will be no certificate). Right click the certificate and choose “Export” command under “All tasks”, and system would open certificate export wizard, and then follow the prompt and click “Next” until the wizard asks you whether to export private key. You can choose “Export private key” and keep default value for other options. At last, type the password and the path you want to save, and confirm it. Finally, the export job is done. And the exported certificate is a file of extension of pfx.
   Later when you migrate or reinstall operation system, find out the PFX file, and right click it, then choose “Install PFX”. System would prompt an import wizard, follow the direction of import wizard to finish the operation, then you can read the file encrypted on NTFS partition previously.
   Attention: if you don’t have a backup key, once the operation fails, then you need to reinstall. And the sam