Decrypt pfiles

Hi Dyari,

Thank you for the prompt reply. I can confirm the Encrypt contents to secure data button is unchecked, see image below.

The usb stick is not protected and does not need a password.

The files I am trying to open are xlsx and jpg. Excell doesn't open it but attempts to import it, see below. The jpg files get an error referring to the .pfile format.

Thank you for the clarification.

If the encryption you used was BitLocker or Windows Device Encryption, it normally encrypts the entire drive rather than individual files. If you copied the files to a normal USB drive while Windows was running and the original drive was unlocked, the copied files should normally no longer be protected by BitLocker.

Also, since the Details button under Properties > Advanced is greyed out, this suggests that the files may not be using Windows EFS encryption.

Before try anything else, could you please check one affected file and let me know:

Right-click the file > Properties > Advanced. Is Encrypt contents to secure data checked or unchecked?

What happens exactly when you try to open the file? Please provide the complete error message or a screenshot.

What type of file is it, for example .docx, .xlsx, .pdf, .jpg, etc.?

Can you also confirm whether the USB drive itself is protected with BitLocker? If it is, Windows would normally ask for a BitLocker password or recovery key when accessing the drive.

Please do not format the USB drive or modify the affected files for now.

Hi Dyari,

Thank you for coming back to me. I think I have chosen a generic encryption when installing Windows 11, I recall Bitlocker might have been installed. I have not selected files or folders to encrypt in isolation. It's the entire drive.

I have followed your instruction to check the Details and find which certificate was used, unfortunately the Details button is greyed out.

Thank you,

Alina

Hi,

I'm Dyari. Thanks for reaching out.

Could you confirm how the files were encrypted? Did you encrypt them by right-clicking the folder > Properties > Advanced > Encrypt contents to secure data?

If yes, this is EFS encryption. EFS uses an encryption certificate and private key stored in your original Windows user profile.

Before reinstalling Windows, did you export or back up your EFS certificate, usually as a .PFX file?

If you have the certificate backup, you can import it into your current Windows installation and should then be able to access the files.

If you do not have the original EFS certificate and the previous Windows installation was erased, unfortunately Windows cannot generate the old key again. Signing in with the same Microsoft account does not restore the EFS certificate.

The Microsoft Information Protection Viewer would not help if these files were encrypted using Windows EFS.

You can also right-click one of the affected files > Properties > Advanced > Details to check which certificate was used to encrypt it.

Please keep me posted.