To change the name of the user in several ways.

To open a control panel, then user accounts, select the user and change the name.
In "My computer" to open the "properties", then the computer name tab in the new window that opens, enter the new user name and click OK.
After done the steps, you must restart the computer for the changes to fully take effect.
You can change the user name by writing it into the registry. To do this, the menu "start" in "Run" write "regedit" to open registry editor, find the line: HKEY_LOCAL_MACHINE=>SOFTWARE=>Microsoft=>Windows, and it after CurrentVersion existing user name that you want to change to the new name. When working with the registry be careful and not change any of the information, as it may result in malfunction of the personal computer.
To create a new profile instead of the corrupted user profile, you need in control panel, find the tab "Administration", and in it the tab "computer Management" and "Local users and groups and then users need to rename the profile. To the previously created data is preserved, you need to copy and move them to the new user profile.