if you are using cross cable to connect two PC... be sure you put the same IP Address Class and subnet mask in order for both to communicate... if you are using W2K pro or XP im sure if wala kang IP na specify it will automatically assigned by APIPA (Automatic Private IP Adressing) feauture ng microsoft... malalaman mo kung naka APIPA dahil 169.x.x.x yung start ng IP niya... give more details like try running this command to both pc ipconfig /all para makita kung ano settings nakalagay...