Inspired from and partially derived from the below TechNet Forum posting and from my own Experience.
Suggested by HarryEnri, on this TechNet thread: How to rename a default user directory...
I changed the order presented in the above-linked article, simplifying the entire process, using command-line for some portions, and booting to "safe mode" as the first step.

Someone in the above thread mentioned that a later boot into safe mode would help with open files/application conflicts. Instead, I choose to boot into safe mode as the first step, thus saving time and simplifying the procedure.


Assumptions

1. You are using Windows 7 Professional


For purposes of this article, we will assume the version is Windows 7 Professional. The only noticeable difference in the Home edition is that the Pro version of the “User Manager” is not directly available
in the Home edition so, in Home edition, you will need to go to Control Panel, click on “Users” and rename the user from there.

2. The user to be renamed (and related folder) is named “owner.”


3. The desired new (target) user/folder name for this example is “tjones”


4. The temporary admin account  to be used will be called “temp.”

Steps

1. First, reboot into safe mode.

Click Start, point to the “right-arrow” symbol next to “Shutdown,” then choose “Restart”. During restart, press the “F8” key intermittently, until you see the startup menu selection for booting into various modes. Choose the the option to “Start in Safe Mode.”

2. Log into "safe mode" as a privileged user

Log into safe mode in the same manner as when you log into "normal mode,” as a privileged user. For this example, we can assume that you log in as "owner."

3. Create a new temporary user with administrator privileges.

This account is used to perform the necessary maintenance against the computer account. This account is a temporary account and can be named along those lines. For this example, we create an account name “temp” and we use a password of "Temp@pass1."

  a. Add the "temp" user; from the command prompt, type "net user /add temp Temp@pass1" and press "Enter."
  b. Add the “temp” user to the “administrators” group
; type: "net localgroup administrators temp /add" and press Enter

4. Log out of the current user account.

5. Log into "safe mode" as the new temporary admin user ("temp").

6. Rename the existing user account ("owner") to the new name.


   a. From
the command prompt, type: "netplwiz" and press "Enter." This will take you to the User Accounts control applet.


  
b. Choose the ‘Advanced’ tab, and then click “Advanced” under the “Advanced User Management” section:




  
c. Give the existing account the desired new name.

Highlight “Users” in the left pane, then highlight the account to be changed (“owner,” in this case), then right-click and choose “Rename.” Give the account the desired new name, “tjones” in this example
.





If desired, right-click the new “tjones” account, choose “Properties” and change the “Full Name” section to your desired name, to match your needs.




7. Rename the existing (original) user folder to the desired new folder name.

   a. Login as the new administrator account that you created earlier ("temp," in this case).
  
b. Browse to the “c:\users” folder.
  
c. Rename the folder to the new name

       Right-click the folder to be renamed (“owner” in this case), choose rename and enter the new name (“tjones” in this example)
.





8. Change the "ProfileImagePath" registry key to match the newly-renamed user.


From command prompt, type “regedit” and press Enter. Next, navigate to the following registry key
:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
Find the Profile SID associated with the user you wish to change (“owner,” in this case) by doing a "Find" within the registry editor; or simply browse through the keys within the "ProfileList" key, until you find the one with "ProfileImagePath" of "c:\Users\owner" (in this case). Once found, double-click that ProfileImagePath key and change it to "c:\Users\tjones” (in this case), and click "Ok".



9. Remove the temporary administrator user account ("temp," in this case).


   a. Reboot into "normal mode (let the computer reboot, without choosing any options)
   b. Login with your newly-renamed user ("tjones.")
   c. Go to the command prompt, and then type: "net user temp /delete" and press "Enter."
       The above step (deleting the "temp" admin user) is the final step.


See Also