My Main PC is running Vista. My Backup PC is running XP. My 2 wireless laptops are running XP. When I try to print or access my Main PC (printer attached to it) from either laptop, I am confronted with a box that asks my user name and password. Since I'm the only one using the computors it is annoying to have to sign in when I want to print. How can I disable this? The box has a symbol of a pair of keys and if I put the ? over the user name it says "user name required by server". This is something new, didn't used to do this.