Today tip is very useful particularly for expert users who want to
create hidden or backup user accounts in windows XP. This trick permits
an account that is normally
displayed on the
Welcome screen to be hidden from view. To hide the specific user account
from the welcome screen, you need to create a special value under
windows registry key.
Follow the given steps to hide any specific user account on welcome
screen:
To
use this feature, you will need to be logged into your computer with
administrative rights.
Click Start button and type regedit in Run option
then press Enter for next.

Here
locate the location to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\
Winlogon\SpecialAccounts\UserList

Here
in right side panel, right click to create a new DWORD Value
with the name of account to be hidden - the name matches the
users name exactly.

To
modify the "Value data" information as DWORD Value 0 to
hide the account and 1 to display the user then click on Ok
button.

Now
close the registry editor and restart your computer after any changes to
go into effect.
But
next time, if you want to enable specific user account on welcome then
simply change the value of data box to 1 or delete the DWORD Value
item.