No Printer Installed in MS Office

Last week we migrated well over 250 workstations from one Domain to another. Among them were several Win XP-64-bit machines. On one of the 64-bit PC’s, I can’t set a default printer since the migration. Office 2007 is installed. When trying to print a WORD document, the printer box is blank, however a printer can be chosen and the document will print. However, when trying to print EXCEL or from Outlook, a message box comes up stating that a printer isn’t installed. Also, in the printer list, there is no mark on any indicating a default. Other applications do print. What am I missing??? Thanks!