With a new computer (XP)I set up a network with the old one (Also XP). This
morning the old computer Network Places told me that they couldn't open
files. Shortly after all the folders and files old computer's My Network
Places just disappeared.

Network Places folders & files seem normal on new computer except that the
old computer stuff also simply disappeared.

Yet I just printed a page from the old computer which accesses the printer
through a router.

Do I go through the complete setup process again? Or might there be
something else at work here?

Help would be greatly appreciated.