sharing files and printers on XP

I am trying to share directories and printers on an XP pro pc with a windows 98 machine, but whenever I try to connect I am asked for a password. I have not setup any passwords and any I try all come back as wrong. I have simple sharing turned off so that Sophos can update the XP machines anti-virus systems.

What am I doing wrong? Another PC running XP dosn’t have this problem.