OK, this one I've never seen before. Went to a user's desk to join them onto our new Exchange domain, went into Control Panel, System applet, and Computer Name tab, and clicked "Change" (the Network ID button was greyed out). When the name change dialog appeared, both the Workgroup Name and Domain Name frame was grey! Couldn't even select one or the other! I can change the computer name, but that doesn't do me any good!! 
I've got XP/Pro, SP2, latest patches and everything; logged in as Administrator; no problem with domain or network configuration (other machines have joined the domain without a single hitch).
Help!! Suggestions? I'm certain of everything noted above (I'm the SysAdmin for a large domain, but this one I've never seen before!)...
Thanks!
SteveB
I've got XP/Pro, SP2, latest patches and everything; logged in as Administrator; no problem with domain or network configuration (other machines have joined the domain without a single hitch).
Help!! Suggestions? I'm certain of everything noted above (I'm the SysAdmin for a large domain, but this one I've never seen before!)...
Thanks!
SteveB