[wlug] passwords

hey all I have a dell laptop (Inspiron 3200) running Ubuntu 5.10 (very well to I might add, not like the 64bit Ubuntu 8.04 on my acer). Anyhow, when I want to look at files on that machine via. LAN, I am presented with a password dialog box. When I enter my password that I use as admin on that machine, It tells me that the password is wrong. Can anyone tell me where in the the filesystem is the file that contains the passwords, that I can edit with GEDIT? Glenn