Issues after taking ownership of C:\

Hi there. I've been rather stupid and transferred ownership of C:\, including system32, to my account (the administrator and only user). While I would instantly switch it back, due to an unrelated reason I restarted my computer (Surface Pro 4). Since then I've done research and found that it was definitely not a good idea to transfer ownership to begin with.

When I turn the computer on, it boots up normally until the point where it (presumably) leads to the login screen, but remains with the spinning-dots loading symbol. After some experimentation it still responds to the keyboard shortcut to change brightness. Also, upon CTRL+ALT+DELETE it goes to the normal screen except without any text. The buttons for wifi, ease of access, and sleep/shutdown/restart on the bottom-right are present and do work. When I hold down the power button the normal 'slide to shutdown' screen appears and is functional.

Is there any solution? Since I can't log in or access File Explorer (or Command Prompt) I can't reset permissions.

Many thanks for any help at all.

essenbe said:

I don't know if it can do what you need, but you can get access to the command prompt from installation media Command Prompt at Boot - Open in Windows 10 - Windows 10 Forums

Thanks for the response. After doing some more digging I've found a way to access that, and am currently looking through other places to find the right command (I'm only familiar with Unix).

Just a thought, but what about creating a Bootable PE Rescue Disk?

To be honest, I just discovered this myself, but it looked like it might offer some help.


b1rd

b1rd said:

Just a thought, but what about creating a Bootable PE Rescue Disk?

If this is what I think it is, then it's sadly not really possible. When I tried to make a bootable USB (since I don't have any essential personal files), it became apparent that you need another Windows machine to set it up. This is another problem, because I am surrounded by Macs. I don't have access to any other Windows computers very easily at all.

In response to my previous post, I've been trying to change permissions for System32, C:\Windows, and now the entirety of C:\ to TrustedInstaller (the default) through command line. Although it says that it's successful, each time I subsequently restart it doesn't work. I'll try a few more variations thereof, regardless.

Thanks once again.

essenbe said:

What command did you use to take ownership?

Code:

icacls C:\ /setowner "NT SERVICE\TrustedInstaller" /T /C

I used

Code:

takeown /F C:\Windows /A

beforehand when trying to do it just for the Windows folder, as suggested by another forum.

EDIT:
My attempt to use the first command has finished and hasn't worked.

I see. Thank you regardless, especially for your speedy response. If it's impossible then I'll just reset the machine and make sure I learn from this mistake.