Nascondere un utente al logon

Hide User Accounts in windows Vista and Windows 7
at Run type regedit
Once in regedit go to HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon

In the left panel, right click on Winlogon and click New and click Key.

Type SpecialAccounts and press Enter

In the left panel, right click on SpecialAccounts and click New and click Key.

Type UserList and press Enter.

In right panel of UserList, right click on a empty area and click New then click DWORD (32bit) Value.

Type in the name of the user account that you want to hide and press Enter.eg: Everyday Account.

In the right panel, right click on the user account name and click Modify.

To hide the user account – Type 0 and click OK. (number zero not the letter)
Whenever you want to use the account just unhide the it by typing 1 instead of zero.