Can't login "the useer profile service failed to sign in"

Question

So a few days back my friend came home and to prank he took user access from my local disk c. I couldn't open it nor could I take back my perms from properties tab. So i rebooted my laptop to advanced recovery then I command prompt I typed /cacls ":C" Reset perms /f /y s something like that from chatgpt then I tried to restart the pc all my pc accounts disappeared there was only the first one and when I tried to log in it gave "the user profile service failed to sign in error". Before entering the command I has system restore points but now they disappeared too. I tried to reset with keep my files and cloud install windows but it didn't work. Surprisingly all my files are safe in system, I can see them while searching for system recovery image. Please help me I don't want to lose my files they are very important.

Answer 1

Hey CoolAxe,

I’ve actually seen this happen before — it’s more common than you’d think when someone tries to mess with NTFS permissions using commands like cacls on the system drive. What probably happened is that the permissions on your C: drive (including critical system folders like C:\Users, C:\Windows, etc.) got wiped or misconfigured. That would explain why:

Your user accounts disappeared

You’re getting the “User Profile Service failed to sign in” error

System restore points vanished

And your reset attempts aren’t working properly

The good news is that your files are still there — and since you can see them while browsing from recovery mode, there’s still a safe way to get them out.

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Here’s What You Can Do to Save Your Files

Use Recovery Mode’s File Explorer Trick

1. Boot into Windows Recovery by turning your PC on and off 3 times during boot (this usually forces it into recovery).
2. Choose Advanced Options > Command Prompt.
3. Once it opens, type:

      Copy
      notepad.exe
   

   Sounds weird, but it works. Go to File > Open, then change file type to All Files.
4. Plug in a USB drive — it should show up on the left or under “This PC”.
5. Navigate to:

C:\Users\<your username>

6. Copy and paste your files to the USB drive.

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If That Doesn’t Work: Boot from a Linux USB

This method saved me once:

1. On another computer, download Ubuntu: https://ubuntu.com/download/desktop
2. Create a bootable USB with Rufus: https://rufus.ie/
   1. Plug it into your laptop and boot from it (usually F12 or ESC during startup).
   2. Choose “Try Ubuntu” (don’t install).
   3. Once the desktop loads, open the file manager. Your Windows drive should show up.
   4. Open it, find your files, and copy them to an external drive.
   Ubuntu ignores broken Windows permissions — so it’ll let you access the files even if Windows won't.

What to Do After You’ve Saved Your Files

Once your data is safe, the cleanest fix is to reinstall Windows completely.

Use the Windows 10 Media Creation Tool to make a bootable USB

Boot from the USB

Choose Custom Install, delete all partitions, and install fresh

That’ll give you a clean slate and fix all the permission/profile issues.

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Let me know if you want help creating the USB or walking through the steps — happy to guide you. Just don’t try more permission resets with command line tools — it usually makes things worse from here.

Hope this helps,