Hi nihil ,
I did what you had told me todo i downloaded the sam spade and run it.
Gave www.yahoo.com and clicked trace . And It started traceing .
it scan the the same default gateway and tried the second one but could not get through
the send system which was the main gateway although it found the main gateway. which it think is running some firewall or have some iptables prolicies set. although the main gateway is router and the second is pc not responding to packets with 0 ttl. Although it found the main system which was stopping the packets . Last time when i posted i was using linux and traceroute could not find that pc with firewall but before reading your post i used the windows2000's tracert and it worked the same way as sam spade . so what you think. about it . how can i trace the route behind that blocking pc. Thanks alot for helping me out. Although it is one step more to find the real prob. Thanks again.