1. Type regedit in the search and open Regedit
2. Find this key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
3. There should be some folders starting with S-1-5. Click on each folder and find if any of it has the ProfileImagePath with your new user account name.
4. If there are two folders, rename the one with .bak extension to be the main one
5. Find keys RefCount and State and set the value to 0 by double clicking on them.