|Just remember that there two ways to change a user.|
One is simply change the logon screen user name. The real user name will still remain and you may need to know that for technical reason.
The other way is to make a new user and then delete the old user.
The best way is to make and have one admin user and put a good password on it. Then make a limited or standard user to use at all times. Use runas to then use any admin tools.
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.