HOWTO Completly Remove a User Account
When you delete a user account from Windows, you only delete the related credentials. All files related to the account are left untouched. You can remove them by the following steps: press <windows_key> + R type ‘sysdm.cpl‘ click on ‘Advanced‘ tab press User Profiles ‘Settings‘ button. select any Unknown entries and press ‘Delete‘ button. This can free several disk MBs.