it is so easy to edit the welcome name in Windows XP Professional...
Just Follow These Steps
Start --- Run --- CMD --- cd c:\windows\system32 and press enter
now type edit and press enter
now go to file -- open and open the file logonui.exe and (X) check on open binary mode and Then Ok
NOw Press Ctrl + END to Come at end of File.... and press page up button... and search for word welcome
now chnage it with another name like (ComeWel) and click on file and then to save as...
Remember that you need to save as it not to save.... ok
so Now give an another name like comewel.exe and click on ok
now close the cmd prompt
now go to start -- run -- regedit
and navigate to the following path==========
mycomputer\hkeylocalmachine\software\microsoft\windowsNT\currentversion\winlogon
and now on the right side....
you will find a file name with UIHOst and open it by double clicking upon it..
so now type Comewel.exe in place of Logonui.exe
now logoff the system and you will find that you have changed the welcome screen with new word (Comewel)
its working