A User Profile is a collection of settings and data of a user account. It is stored in the user's C:\Users\<user name> profile folder.

Temporary User Profile:

 A temporary profile is created each time that an error condition prevents the user's profile from loading. Temporary profiles are deleted at the end of each session, and changes made by the user to desktop settings and files are lost when the user logs off.

If a user signs in to their account and gets 'We can't sign into your account' message and 'You've been signed in with a temporary profile' notification message below, then that user has been signed in to a temporary profile (eg: C:\Users\TEMP) instead of the profile from their C:\Users\<user-name> profile folder. Any changes that the user makes to the temporary profile are lost after signing-out.

error messages:-

We can't sign into your account:

You've been signed in with a temporary profile:

Troubleshooting:-

Important: To be extra safe, it’s recommended to back-up your "C:\Users\<user-name>" profile folder.

Step 1: Restart your computer multiple times

1) Restart your device in safe mode and sign in with your original profile. Check to see if your settings and files are restored.

2) Restart your device in normal mode and sign in again with your original profile. Check to see if your settings and files are restored. (You might need to restart your device more than once.)

3) If multiple restarts don't help, try temporarily disabling your antivirus software & disable Windows Defender services (Change ‘Windows Defender Advanced Threat Protection’ and ‘Microsoft Defender Antivirus’ services’ Startup type to Disabled and Restart your PC) which might scan your device during sign-in.

Step 2: REGISTRY FIX 

1. While signed in to the account with the temporary profile, open a command prompt.

2. Enter "whoami /user" command to get SID (Security Identifier, a SID is a string value that is used to uniquely identify users.)

   SID eg.: S-1-5-21-2171760768-3957144033-4256508931-1001

   

3. Open ‘Registry Editor’ (type ‘regedit’ in Run)

    

4. Navigate to the ProfileList key:

   >HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

   

5. In the left pane under the expanded ProfileList key, look to see if the SID key from step 2 above is listed with .bak (eg: S-1-5-21-....-1001.bak) and/or without .bak (eg: S-1-5-21-....-1001) at the end. (see screenshot above)

   1. If the SID key is without .bak:

      1. In the right panel of the SID key (eg: S-1-5-21-....-1001), double click on the ProfileImagePath value name to modify it.

      2. Enter the correct path (eg: C:\Users\<user-name>) of the user's profile folder, and click OK.

      3. Verify that the State DWORD is set with a value data of 0 (number zero).

   2. If the SID key is with .bak:

      1. Right click on the SID key (eg: S-1-5-21-....-1001.bak), click on Rename, and rename the SID key to only remove ".bak" (eg: S-1-5-21-....-1001) at the end of the key's name.

      2. In the right panel of the SID key (eg: S-1-5-21-....-1001) now without .bak at the end, double click on the ProfileImagePath value name to modify it.

      3. Enter the correct path (eg: C:\Users\<user-name>) of the user's profile folder, and click OK.

      4. Verify that the State DWORD is set with a value data of 0 (number zero).

   3. If the SID key is without and with .bak:

      1. Right click on the SID key without .bak (eg: S-1-5-21-....-1001), and click on Delete.

      2. Right click on the SID key with .bak (eg: S-1-5-21-....-1001.bak), click on Rename, and rename the SID key to only remove ".bak" (eg: S-1-5-21-....-1001) at the end of the key's name.

      3. In the right panel of the SID key (eg: S-1-5-21-....-1001) now without .bak at the end, double click on the ProfileImagePath value name to modify it.

      4. Enter the correct path (eg: C:\Users\<user-name>) of the user's profile folder, and click OK.

      5. Verify that the State DWORD is set with a value data of 0 (number zero).

6. Exit Registry Editor & Restart the computer, and sign in to the account that got the temporary profile error to see if it’s fixed.

7. If the account's profile is still not fixed, then you can create a new user profile for the account, and copy over any files you want from the old profile folder to the new one afterwards.