[help]my modfied logon screen won't load

I have changed all the logonui to logonui.bak manually so that the computer won't reload the original file. I then replaced it with a different logonui and when I log off the winXP logon is still there. I have two computers and done the same to computer A and it worked, but it doesn't work on computer B.

both are running XP pro. Can someone give me some advice.

#225979