Hi everybodyI have a question. I had turned on Bitlocker and decrypted 2 HD. Now my prob is. I want to reinstall Windows 7. So can i use the same key to unlock the HD after the reinstallation or should i have to use the main key to recover the HD or should i encrypt the HD first and then reinstall windows 7. Thanks for your help...DannyDN

To decrypt a folder or file Right-click the folder or file you want to decrypt, and then click Properties. Click the General tab, and then click Advanced. Clear the Encrypt contents to secure data check box, and then click OK. You should back up your EFS certificate to make sure that you can access your encrypted data if something happens to the encryption key. For more information, see Back up Encrypting File System (EFS) certificate.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. To back up your EFS certificate open Certificate Manager. (run 'certmgr.msc' ) In the left pane, double-click Personal. Click Certificates. In the main pane, 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. Click Finish.Rating posts helps other users Mark L. Ferguson MS-MVP