Hidden User Account

An account that is normally displayed on the Welcome screen can be hidden from view. To log on using the account it's necessary to use the Log On To Windows dialog box similar to 

the one in Windows 2000. 

• Navigate to the following registry key:  
  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon\SpecialAccounts\UserList. 
• Right Click on the right side window and create a new DWord value. Name the key, the name of account to be hidden. For example, If I wish to hide an account called “Rahul”, 
  then I name the key as “Rahul”. 
• Set the value 0 to hide that account. 
• Now exit the registry editor and reboot. 

To display the account at a later period, visit the same key and give the value 1. 
Now you have an account  hidden

NOTE :- Take the backup of your registry (by one of these Software's) before doing any tweak.