Thank You very much Harry for your reply , I'll take some time to read, understand your post and do some googling before my next post. However before that somethat i've done yesterday is this

ifconfig command in Knoppix gives me this :
eth0 Link encap:Ethernet HWaddr 00:00:E8:00:44:BF
inet addr:192.168.0.5 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::200:e8ff:fe00:44bf/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:19051 errors:0 dropped:0 overruns:0 frame:0
TX packets:39 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1947818 (1.8 MiB) TX bytes:3758 (3.6 KiB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:22 errors:0 dropped:0 overruns:0 frame:0
TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1100 (1.0 KiB) TX bytes:1100 (1.0 KiB)

How do I interpret this ?? How do I use these commands with the above data
1) sudo ifconfig eth0 inet x.x.x.x
2)sudo ifconfig eth0 netmask 2555.255.255.0 broadcast x.x.x.x (you said 192.168.3.255)

Thank you very much for being so helpful. I'll do some research on whatever you have posted here and come up in my next reply, but honestly speaking I did some googling before posting this query and I also searched this forum.