When setting up a new Windows 11 system or adding a new user account in Windows 11, an accompanying user profile folder is automatically created in the C:\Users directory. By default, Windows does this really annoying thing where it only utilizes the first five characters of the user account name as the name for this profile folder. Thanks to lots of smart people on the internet it is possible to change the account name and user directory to what it should have been originally. These are my instructions, shamelessly pulled from other sources.
(1) Login with a different user account.
I’m going to skip the part where I tell you how to use the Administrator account to login because — let’s be real here — if you don’t know how to do that you really shouldn’t be mucking around in the registry.
(2) Get the SSID of your user account.
Open powershell, terminal, or cmd.exe as an administrator and run the commandwmic useraccount get name,SID
You’re looking for output similar to username S-1-5-21-3865857740-2209249665-nnnnnnnnnn-1001
(3) Change the registry key ProfileImagePath.
Run regedt32, navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\S-1-5-21-3865857740-2209249665-nnnnnnnnnn-1001 (from above), and change the registry key ProfileImagePath from C:\Users\xxxxx to C:\Users\full_name. When finished, close the Registry Editor.
(4) Rename the user directory.
From command line (e.g. powershell, terminal or cmd.exe) or the File Explorer, navigate to the C:\Users folder and change the name of xxxxx to full_name.
(5) Rename the user (for completeness).
Open Computer Management, navigate to Local Users and Groups –> Users, and rename xxxxx to full_name.
(6) Reboot the computer
That’s it! You should still be able to login as before, but now your user directory will be your full username and not the shortened name. Enjoy!