How can I make my welcome screen reappear on my PC?

I have a Windows XP and am logged in as an administrator. My Welcome screen that allows for choosing a user no longer appears. Instead, there is the center square that requires the Alt+Ctrl+Del option. I went to my control panel and found the "Change the way users log on or off" option to find the message that read something along the lines of "Must uninstall Client Services for NetWare" What does this mean and how do I do it?