Hey thanks to both of you. I agree that its not a big threat i checked my windows firewall log and found no entry for the IP. but norton log shows that it was a XMAS_null scan.

and KorpDeath please tell me which is a good firewall is BlackIce better then Norton. i also agree that no firewall is going to keep my system completly protected. but i would love to learn more. I am new to the field and i would love to have more information.