When you install windows, you will enter a user name, which is usually set to admin by the computer store. At this time, if you want to change it to your own, you usually modify it directly in Control Panel > user accounts and family safety > user accounts > change account name.
After the change, the user name displayed on the start menu is your own, but the main account folder under the C: users folder is still the original name. Open and run, enter CMD, enter, and the user name above is still the original name. If you want to change these places, you need to use the following method.
Open run, enter CMD and enter;
inputcontrol userpasswords2, enter;
Click properties, modify user name, and click OK;
Open run, inputregedit, enter;
Navigate toHKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList；
Select the item with the longest name below, double-click profile imagepath on the right, modify the user name after C: \;
Log out and log in again;
Open C: user, delete the new user name folder, and then rename the original user name folder to a new user name;
Log out again and log in again.