Hello!
This is usually a symptom of a Temporary User. Check to see if you are not on a temporary user.
ATTENTION:
- Before performing any solution, check if your data is saved. Press the WINDOWS + R keys to open Run > Type "C:\Users" (without quotes).
- Open the folder with the name of your original User Profile.
- Check if your data is saved in the Desktop, Documents, Pictures, Downloads, Videos and Music folders.
- Save your data to an External Drive or Cloud as a precaution (Make a Backup).
Restart your computer a few times and see if you can access your original user profile.
Another solution that may help:
- Navigate to the Users folder. Press the WINDOWS + R keys to open Run > Type "C:\Users" (without quotes).
- If there is a folder named TEMP (Temporary User Folder), delete the Folder > Restart the computer.