As Sistem Administrator sometimes it’s useful add new users to the system to run some services in a clean environment (antivirus, update critical software) but if you use a visual login (not CTRL+ALT+DELETE way) you may want also to hide this clean-user to the others so i write a small guide to obtain this result.

Open run tab and digit

Make a registry back-up to restore in case of fault

Search for this registry key:

If you are a Seven or Vista user you can't find this key so we need a few passage before xp user that can jump at Passage 6 of this guide

Search for

Right-click on Winlogon voice and select New –> Key

Name it "SpecialAccounts"

Right-click on SpecialAccounts and select New –> Key

Name it "UserList"

Right-click in a empty area of a right panel and select New –> DWORD (32-bit) Value

Name it as the user you want hide in the login screen

Double clik on it and write "0" in the field instead of "1"

Now you can restart the system and check for the result

If you need to use this "user" you can press CTRL+ALT+DELETE double in visual login screen and in the new screen that appear insert user and password of the hidden user.