Adding second lane microsoft pos 2.0 Access Denied problem.

I have microsoft pos 2.0 on a windows vista business machine. I am running a peer to peer network. The second machine with xp pro is the computer im tring to add the second pos system too. The computers are all in the same workgroup and all the firewalls are off. Im still getting an error message "an error occured while attempting to create users and groups for point of sale. " Then it says access denied. I can see the database on the xp vista machine just when I try to login on the xp pro machine it gives me the error message. Any advice is much appreciated. thanks