Access folder on read-only disk with no NTFS permissions

Question

I have an interesting situation; my main OS hard drive has started to go bad. It's an SSD, and according to the manufacturer, when this happens it automatically switches to a read-only state to preserve my data.

I'm unable to boot into the original Windows 10 OS because of corruption on the disk. I'm now reading the drive from a different install of Windows 10, but one of the folders is inaccessible because the new OS doesn't have access to read it and my local admin account is not an owner of that folder.

So I'm stuck; I can't access the folder because I don't have permissions and I can't change permissions because the drive is in a ready only state.

How can I get access to the data so I can recover it?

Answer 1

If you have enough free space on another computer (slightly more than the used space in your broken disk), clone the disk into a VHD image. (I would use Disk2vhd for that, even though it's not exactly a backup tool.) Windows 10 can natively attach VHD/VHDX images as writable virtual disks, which lets you take ownership of the files, then give yourself full permissions to those.

Alternatively, find a program which uses SeBackupPrivilege. This privilege, held by administrators, allows opening files "with backup intent" bypassing permission checks – so that backup software could make a copy of everyone's files. One such tool I just found is a PowerShell module on GitHub.

Alternatively, use a Linux computer (e.g. boot a Ubuntu live CD) – by default, the ntfs-3g driver completely ignores NTFS permissions and behaves as if it were ordinary FAT.

Answer 2

Most folders, notably user profile folders, allow access to the local Administrators group, which has the same security identifier on all systems. Therefore, an administrative command prompt should be able to navigate into them and copy the data out.

If that isn't sufficient privilege, you could boot the machine into the recovery menu and use the command prompt there. The recovery environment is a stripped down version of Windows that generally doesn't respect access control lists.

Another approach is to use Disk2vhd to copy the drive into a virtual hard disk (VHD) that you can modify permissions on. Accept the EULA, deselect all the volumes except the main one from the old disk, select a path to save the VHD at, make sure "Use Vhdx" is unchecked, and click Create. If you get an error, toggle the "Use Volume Shadow Copy" checkbox and try again. Once the copy completes, you can close Disk2vhd. Double-click the generated VHD file in File Explorer and it will be mounted, appearing like any other drive. You can make any changes you want to the virtual drive and it won't affect the original. Once you're done, you can right-click the mounted volume and choose Eject.