1.Open Regedit: Start > Run > Regedit
2.Navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
3.On the left, right click on Winlogon, click New and click Key.
4.Type SpecialAccounts and Enter.
5.On the left, right click on SpecialAccounts, click New and click Key.
6.Type UserList and Enter.
7.In the right panel of UserList, right click on a empty area and click New then click DWORD (32bit) Value.
8.Here, type in the name of the user you want to hide, example: Administrator.
9.Right click on the user account name and click Modify.
10.To hide the user account type 0 and click OK.
Remember, you must do this for each user account you want to hide.
If you want to show the user account again, enter 1, instead of 0 at the last step.