Access denied on a drive from your old PC? Read this

You’ve taken the hard drive out of an old computer, connected it to your new one, and Windows won’t let you in. Folders say “You don’t currently have permission to access this folder” or “Access is denied”. Some files copy across but won’t open; others have green names. It’s easy to assume the drive is broken, but most of the time the data is perfectly intact and Windows is doing exactly what it was set up to do. The trick is working out which of three very different things is blocking you, because the fix for one does nothing for the others.

1. Ordinary NTFS permissions

Every file and folder on an NTFS drive records which user accounts are allowed to open it. Those accounts are stored as unique security identifiers belonging to the old Windows installation. Your new PC has never heard of them, so your user folders – Desktop, Documents, Pictures – from the old drive can appear locked even though you are an administrator.

This is the easiest case. The data isn’t encrypted; Windows is just checking a list of names. An administrator can take ownership of the folder through Properties > Security > Advanced and change the owner to their own account, then grant themselves access. Do it only on the folders you need (your old user folder, for example), rather than the whole drive or the old Windows folder, and copy the files to your new PC once you can open them.

2. EFS-encrypted files

Windows Pro, Enterprise and Education include the Encrypting File System (EFS), which encrypts individual files and folders. By default Explorer shows EFS-encrypted files with green file names, sometimes with a small padlock on the icon. Some people turned it on deliberately; others ticked “Encrypt contents to secure data” years ago and forgot.

EFS is where people come unstuck. The key that unlocks those files is protected by a certificate that lived in the old user’s Windows profile, which in turn is protected by that user’s password. On the new PC:

• Taking ownership succeeds, but the files still won’t open – ownership and encryption are separate.
• Copying the files can fail with “Access is denied”, or produce copies that are still encrypted.
• Running decryption tools or “fixing” permissions repeatedly doesn’t help and can make the situation harder to unpick.

If the old PC still starts, this is easy to solve: log in as the old user and either copy the files elsewhere while logged in (which can leave them encrypted, so check) or, better, back up the EFS certificate with its private key to a password-protected file and import it on the new PC. Microsoft documents both steps, using Certificate Manager or the cipher command.

If the old PC won’t start but its drive is healthy, the key material is still inside the old user profile on that drive. With the old account’s password it can sometimes be used to decrypt the files, but this is specialist work. Without the password and the old profile, EFS files generally can’t be decrypted. So whatever you do, don’t wipe or reinstall Windows on the old drive and don’t delete the old user folder – that’s where the keys are.

3. BitLocker

If the whole drive asks for a password or a recovery key, or shows a padlock in File Explorer, it’s BitLocker drive encryption rather than file permissions. No amount of taking ownership will get past it. You need the 48-digit recovery key, which is often saved in the Microsoft account the old PC used, in a work organisation’s records, or on a printout or USB stick from when BitLocker was set up. Many newer laptops turn on device encryption automatically, so it can be on without you ever having chosen it.

Quick ways to tell which one you have

• Folder won’t open, files have normal names: almost always permissions.
• Green file names or padlock icons on files: EFS.
• The whole drive asks for a password or key: BitLocker.
• Folders open slowly, the drive clicks or disconnects, or files are corrupt: the drive itself may be failing. Stop and don’t run repair tools on it.

What not to do

• Don’t run CHKDSK on the drive to “fix” access problems. It isn’t a permissions tool, and on a weak drive it can make things worse.
• Don’t format the drive or let Windows “initialise” it because something won’t open.
• Don’t reinstall Windows on the old drive to get back in – it replaces the profile that holds any EFS keys.
• Don’t dispose of or recycle the old PC until you’ve confirmed every file opens on the new one.

When to get help

If the old drive is making noises, disconnecting or is very slow, or you’re facing EFS-encrypted files with no working old PC, it’s time to stop experimenting. We can image the drive safely and work from the copy, whether it’s an internal drive or a WD external hard drive that has been used as a backup.

Call Data Retrieval on 020 7064 4996 or request a quote. We offer a free assessment, with no obligation.