NETWORK PASSWORD REQUEST

Hello,
I have just set up a local network of 3 computers in my home. They worked fine the first night, could access and print from the network printer. The next day when I tried it it would not hook up at all, so ran network wizzard and set it up again. Now they all show up and I can access two of the computers but on the third computer it ask for a password when I try to access the computer with the network printer. It will not let me print and I am assuming I can't access the printer either. There is no password on the computer that is asking for a password. I am running XP SP2. Any suggestions?????