# Fix "User Profile Service Failed the Sign-In" in Windows 11

URL: https://www.mytechnician.tech/tips/fix-user-profile-service-failed-sign-in-windows-11/
Published: 2026-08-05 | Author: Ankit Kumar
Tags: Windows 11, Troubleshooting, Fix, System, Files
Summary: Locked out with "The User Profile Service service failed the sign-in"? Repair the profile entry in the registry and get your account and files back.

## The Problem
**"The User Profile Service service failed the sign-in. User profile cannot be loaded."** appears after you enter your password and stops you at the sign-in screen. The account exists and the password is right — Windows simply cannot open the profile behind it.

Windows keeps a list of every profile in the registry, with a path to the matching folder in `C:\Users`. Sign-in fails when that record and the folder disagree: the entry has been marked as a backup with a `.bak` suffix, the path points somewhere that no longer exists, or the profile status flags say the last load did not finish. That happens after an unexpected shutdown, a disk that filled up mid-login, an antivirus quarantining part of the profile, or a failed update.

**Your files are almost always still there**, sitting in `C:\Users\<yourname>`. This is a broken pointer, not a deletion.

> **Getting in but with an empty desktop and a warning about a temporary profile instead?** Closely related, different fix — see [fix "signed in with a temporary profile"](https://www.mytechnician.tech/tips/fix-temporary-profile-windows-11/).

## Symptoms
* **"The User Profile Service service failed the sign-in"** after entering the correct password.
* One account fails while other accounts on the same PC sign in normally.
* Started after a forced shutdown, a full disk, a Windows update, or an antivirus scan.
* `C:\Users` may contain both `yourname` and `yourname.000` or `TEMP`.

## Step 1: Restart and Free Up Disk Space
The simplest causes first — a genuinely full system drive prevents a profile loading at all.

1. Restart the PC properly rather than powering it off. If you can only reach the sign-in screen, use the power icon in the bottom-right → **Restart**.
2. Sign in to any other working account, or the built-in administrator, and check free space: **Settings** → **System** → **Storage**.
3. Anything under about 10 GB free on `C:` is likely the cause. Clear space: [free up disk space when the C drive is full](https://www.mytechnician.tech/tips/free-up-disk-space-c-drive-full-windows-11/).
4. Try the failing account again before doing anything more invasive.

## Step 2: Get In Using Safe Mode or Another Admin Account
You need a working session to make the repair.

1. If another administrator account works, sign in there.
2. Otherwise use Safe Mode: hold **Shift** while clicking **Restart** on the sign-in screen → **Troubleshoot** → **Advanced options** → **Startup Settings** → **Restart** → press **4**.
3. Full routes: [how to enter Safe Mode in Windows 11](https://www.mytechnician.tech/tips/how-to-enter-safe-mode-windows-11/).
4. If you have no other admin account and Safe Mode still fails, go to Step 6 and work from the recovery environment.

## Step 3: Repair the Profile Entry in the Registry
This is the fix that resolves most cases. Take the backup in the first sub-step — registry edits are easy to get wrong.

1. **Windows + R** → `regedit` → Enter. In Registry Editor, select **File** → **Export**, save a full backup, and keep it somewhere you can reach.
2. Navigate to:
   ```
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
   ```
3. Click each `S-1-5-21-…` subkey and read **ProfileImagePath** on the right until you find the one ending in your username.
4. **If you see two keys for the same user — one plain and one ending `.bak`:**
   * Rename the plain key by adding `.temp` to the end.
   * Rename the `.bak` key to remove `.bak`.
   * Rename the `.temp` key to end in `.bak`.
   * You have now swapped them: the good profile record is live again.
5. **If you see only one key**, work with that one.
6. In the now-live key, double-click **State** and set its value data to **0**. If a **RefCount** value exists, set it to **0** as well.
7. Confirm **ProfileImagePath** points at the real folder, for example `C:\Users\ankit`. Correct it if it points at a `.000` or `TEMP` path.
8. Close Registry Editor and restart.

## Step 4: Check the Profile Folder Permissions
1. Open `C:\Users` and right-click your profile folder → **Properties** → **Security**.
2. Your account should be listed with **Full control**, alongside **SYSTEM** and **Administrators**.
3. If it is not, click **Advanced** → **Change** beside Owner, type your username, click **Check Names**, then **OK**. Tick **Replace owner on subcontainers and objects** and apply.
4. Back on the **Security** tab, click **Edit** and grant your account **Full control**.
5. If the ownership route is unfamiliar, the same procedure is walked through in [fix access denied and "you need permission"](https://www.mytechnician.tech/tips/fix-access-denied-you-need-permission-windows-11/).

## Step 5: Repair the Default Profile
Windows copies `C:\Users\Default` whenever it builds a profile. If that template is damaged, new profiles fail too.

1. In File Explorer, enable **View** → **Show** → **Hidden items**, then open `C:\Users\Default`.
2. Confirm the folder exists and contains `NTUSER.DAT`. A missing or zero-byte `NTUSER.DAT` is the problem.
3. Copy `C:\Users\Default` from a working PC on the same Windows 11 build, or restore it from a restore point.
4. Then repair the system files: [how to run SFC and DISM](https://www.mytechnician.tech/tips/how-to-run-sfc-dism-repair-windows-11/).

## Step 6: Use System Restore From the Recovery Environment
If you cannot sign in to any account.

1. Interrupt the boot three times to reach **Automatic Repair**, then choose **Advanced options**.
2. Select **Troubleshoot** → **Advanced options** → **System Restore**.
3. Pick a restore point dated before the sign-in started failing.
4. If no restore points exist, choose **Startup Repair** instead.
5. Related: [fix the automatic repair loop](https://www.mytechnician.tech/tips/fix-automatic-repair-loop-windows-11/) and [create a system restore point](https://www.mytechnician.tech/tips/create-system-restore-point-windows-11/) so this option exists next time.

## Step 7: Rule Out Antivirus and Check the Disk
1. If a third-party security suite is installed, uninstall it from the working account and run the vendor's removal tool. Suites quarantining `NTUSER.DAT` cause exactly this failure.
2. Microsoft Defender takes over automatically: [fix Windows Defender not working](https://www.mytechnician.tech/tips/fix-windows-defender-not-working/).
3. Check the file system from **Terminal (Admin)**:
   ```
   chkdsk C: /f /r
   ```
   Press **Y** to schedule, reboot, and let it finish.
4. Check the drive's health too: [check SSD and hard drive health](https://www.mytechnician.tech/tips/check-ssd-hard-drive-health-windows-11/).

## Step 8: Build a New Profile and Move Your Files Across
When the old profile cannot be repaired, this recovers everything that matters. A damaged profile is not worth days of fighting.

1. From the working admin account: **Settings** → **Accounts** → **Other users** → **Add account** → **I don't have this person's sign-in information** → **Add a user without a Microsoft account**.
2. Create the account, then set it to **Administrator** under **Change account type**.
3. Sign in to the new account once so Windows builds the profile, then sign out and back into the admin account.
4. Copy your data from `C:\Users\<oldname>` to `C:\Users\<newname>` — **Desktop**, **Documents**, **Pictures**, **Downloads**, **Videos**, and `AppData\Roaming` for app settings. Do **not** copy `NTUSER.DAT` or the whole `AppData` folder; that carries the damage across.
5. Sign in to the new account and link your Microsoft account if you use one: **Settings** → **Accounts** → **Your info** → **Sign in with a Microsoft account instead**.
6. Once everything is confirmed working, delete the old account from **Settings** → **Accounts** → **Other users**.

## What Not to Do
* **Don't delete the profile folder or the registry key** before copying your files out. That is what turns a fixable problem into real data loss.
* **Don't copy `NTUSER.DAT` into the new profile.** It is the file that is usually corrupt.
* **Don't reset or reinstall Windows first.** The files are still on the disk and this is repairable.
* **Don't edit `ProfileList` without exporting a backup.** A mistyped path there stops every account signing in.

## Still Not Working?
If a brand new account also fails to sign in, the problem is system-wide rather than profile-specific — run SFC and DISM, then consider an in-place repair install, which keeps files and apps: [reinstall Windows without losing data](https://www.mytechnician.tech/tips/reinstall-windows-without-losing-data/). Get your data off first: [how to recover deleted files in Windows](https://www.mytechnician.tech/tips/how-to-recover-deleted-files-windows/) and [set up automatic backups](https://www.mytechnician.tech/tips/set-up-automatic-backups/).

Related: [fix "signed in with a temporary profile"](https://www.mytechnician.tech/tips/fix-temporary-profile-windows-11/), [fix Microsoft account sign-in problems](https://www.mytechnician.tech/tips/fix-microsoft-account-sign-in-problems-windows-11/), and [reset a forgotten Windows password](https://www.mytechnician.tech/tips/reset-forgotten-windows-password/).

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Source: https://www.mytechnician.tech/tips/fix-user-profile-service-failed-sign-in-windows-11/ — My Technician, free Windows 10/11 troubleshooting guides.
More guides: https://www.mytechnician.tech/llms.txt