WinXP and Win2000

I have PC "A" running Win 2000 with a printer attached to it. Computer "B"
used to be Win 2000 also until today. Printing from B to A was no problem and
accessinf files was good too. Now I have to enter a network password to get
access to computer A. I have changed the user on the XP machine "B" to be the
same as the Win2000 "A" but that doesn't seem to work. How can I make the B
access and print to to A without entering a password/ remember the password.
Strange thing is though there is no password on computer A

Any clues?

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