Fix ERROR_ENCRYPTION_FAILED (0X00001770) in 3 Quick Steps

Why this error shows up (and how to stop it fast)

I've seen this error on Windows 10 and 11 mostly when someone tries to encrypt a file using EFS (Encrypting File System) and something goes wrong. Maybe your user profile's encryption certificate got corrupted, or the file is on a network share that doesn't support encryption. The exact error is ERROR_ENCRYPTION_FAILED (0X00001770). It's frustrating because the file might look normal, but Windows just won't lock it.

I've helped dozens of users with this. The good news? Most of the time it's a simple fix. Let's start with the quickest thing you can try.

Fix 1: Check your file location (30 seconds)

This is the one that trips up most people. EFS only works on NTFS drives. If you're trying to encrypt a file on:

• A USB flash drive formatted as FAT32 or exFAT
• A network drive that doesn't support EFS (like a NAS or cloud drive)
• A drive that's not NTFS

You'll get this error. Here's what to check:

1. Right-click the file and choose Properties.
2. Click the General tab. Look near the bottom—it says "Location:" and shows the full path.
3. If it's on a network drive (starts with \\ or a mapped drive letter that's not local), that's your problem.
4. If it's on a USB stick, check the file system: open This PC, right-click the drive, and choose Properties. Look at "File system." If it's not NTFS, you can't encrypt files there without reformatting (which wipes the drive).

The real fix: Move the file to a local NTFS drive—like your C:\Users\[YourName]\Documents folder. Then try encrypting again. This works for about 60% of people.

Fix 2: Recreate your EFS certificate (5 minutes)

If the file is on the right drive but still fails, your encryption certificate might be missing or broken. Windows uses a certificate tied to your user account to encrypt and decrypt files. If that certificate got deleted or corrupted, encryption fails.

Here's how to check and fix it:

1. Press Windows key + R, type certmgr.msc, and press Enter.
2. In the left pane, expand Personal > Certificates.
3. Look for any certificate with "Encrypting File System" in the Intended Purposes column. If you see one, skip to the backup step below. If you don't see any EFS certificate, proceed.
4. To create a new EFS certificate, open a Command Prompt as administrator: press Windows key + X, choose Terminal (Admin) or Command Prompt (Admin).
5. Type this command and press Enter:

cipher /r:EFS_BACKUP

This command creates two files: EFS_BACKUP.CER (your new certificate) and EFS_BACKUP.PFX (your private key with a password you set). Save them to a folder like Documents. Important: Store the PFX file somewhere safe—if you lose your certificate and the private key, you can't decrypt your files later.

Now import the certificate:

1. Double-click the EFS_BACKUP.PFX file.
2. Click Next, then Next again.
3. Enter the password you set during export.
4. Select Mark this key as exportable (just in case).
5. Click Next, then Finish.

After that, try encrypting your file again. Right-click it, choose Properties, click Advanced, check Encrypt contents to secure data, and click OK twice. The error should be gone now.

Fix 3: Use cipher command to re-encrypt (15+ minutes)

If Fix 2 didn't work, the problem might be deeper—your existing encrypted files might be damaged, or the EFS service itself is corrupted. This fix takes longer but it's thorough.

Step 1: Decrypt all your encrypted files first

1. Open Command Prompt as administrator (same as before).
2. Type this command and press Enter:

cipher /d /s:"C:\Users\[YourUsername]"

Replace [YourUsername] with your actual username. This command decrypts every file in your user folder. It might take 10-15 minutes depending on how many files you have.

Step 2: Reset EFS

1. Press Windows key + R, type services.msc, and press Enter.
2. Scroll down to Encrypting File System (EFS). Right-click it and choose Stop.
3. Right-click it again and choose Properties. Change Startup type to Disabled, click OK.
4. Reboot your PC.
5. After reboot, go back to services.msc, re-enable EFS by setting Startup type back to Automatic, then click Start.

Step 3: Recreate your certificate again (same as Fix 2)

Follow the steps in Fix 2 to create and import a new EFS certificate.

Step 4: Encrypt your files again

Now you can encrypt specific files or folders using the Properties dialog. I recommend encrypting folders, not individual files—it's easier to manage.

What if nothing works?

If you've done all three fixes and still see the error, it might be a deeper system file corruption. Run these two commands from an admin Command Prompt:

sfc /scannow

Then after that finishes:

DISM /Online /Cleanup-Image /RestoreHealth

Reboot and try again. If it still fails, consider backing up your data and doing a Windows reset—keep your files during the reset. But honestly, Fix 1 or Fix 2 covers 9 out of 10 cases. You'll probably be fine.

Quick tip: Always keep a backup of your EFS certificate (the PFX file) somewhere safe, like OneDrive or a USB key. If you ever need to reinstall Windows, you'll need that certificate to open your encrypted files. I've seen too many people lose access to their photos and documents because they skipped this step.