I've just received a new laptop with a ghosted Windows 7 Professional image. When I go join the machine to the domain I see the 'Domain' text box greyed out (the system is in Spanish) :
My local account has administrator rights. To verify it's not my account that's at fault I've enabled the Administrator account and tried to join, logging in with that account, without any success. Does anyone know why that box is greyed out? The 'Network ID' button is also greyed out in the system properties dialogue box.