On two machines now I have tried to change the user and screwed up both machines. I was asked to remove the existing user (with administrative privalige) and create a new user with administrative privalige. Then remove the old user and all of their files. I went to the User applet and created the new user, logged off as the old user and logged on as the new user. Went back to the User applet and selected the old user and picked the "delete user" option and the "delete user files" option. The PCs worked fine and came back up with the new user on a Shutdown-Restart. However, after a full shutdown, on the next start the 'old logon window' format showed with the new user name and when I tried to start I got the error message "Unable to log on to the Domain. Check User name and Domain for correct entry". (Before I lost the machine I had confirmed that neither the new user, the old user, or the Administrator had passwords.) Even changing the User to "Administrator" resulted in the same error. Then booting into the Safe Mode with exactly the same results. Now neither computer had ever been on a Domain system. Both Computers are Dell Dimension computers with Window XP Pro and I have the Dell Installation disks for both computers, so I tried a Repair Installation. At the end of this effort and reboot, the same error. I have since used the Dell Installation disks to reformat and reinstall the OS and drivers. Connected to the Internet and downloaded the many-many updates. However, now both owners have to reinstall their software and printers. Question: What did I do wrong? I had done this same task to a Dell Windows XP Home Edition before and not had a problem.