Open Ports

Type NETSTAT -A to see all listening ports

compare those with
http://www.good-stuff.co.uk/useful/portfull.php
and figure ould what you can live without

see what processes have ports in use
NETSTAT -O

how about port "1213/udp" or any port(I need to know the process to close open ports, doesn't matter which ones) and how can i close application to close port in windows 98

According to iana.org:
mpc-lifenet     1213/tcp   MPC LIFENET
mpc-lifenet     1213/udp   MPC LIFENET

Now, I don't personally recognize that one, nor do I think it is very common. I checked the NMAP port list (my copy is from October of 2003, so fairly recent), and this port is not in the NMAP-SERVICES common port list.

I would say try running FPORT, which can map open ports to running applications:
http://www.foundstone.com/resources/proddesc/fport.htm
But it looks like FPORT does not work on Win98:
"fport supports Windows NT4, Windows 2000 and Windows XP "

But, luckily, TCPView from Sysinternals, found here:
http://www.sysinternals.com/ntw2k/source/tcpview.shtml
DOES work on Win98.
So, get it, run it, and you can tell what app has the port open! You can then take actions on stopping that application that opens the port.

cyber sitter uses 1213, if you have that going

You have to stop the application from running. Some may be in the startup folder, others may be run from a registry entry.
Note you may break some networking capabilities if you're sharing anything on that machine.
post the output of NETSTAT -A and we'll try to work through them

for windows 98, i don't think it has native support for any sort of firewall or port filtering. however windows 2000 does have support for simple forms of ip filtering

http://support.microsoft.com/default.aspx?kbid=309798

also try this program. it's free - http://download.com.com/3000-2085-10062969.html?part=65960%20&subj=dlpage&tag=button

Actually all ports are closed by design. It is only open when an application is using it example Netbios 137. You can't close all these ports as it means ending the application. All you need to secure is to make sure only you the PC user can use this port by the application used by you and with your permission.I agreed with them about using the IP filtring method. Once you activated it, you can specify what port you want to open. By design all are close. You must find out your need and open the ports accordingly.

how to use IP filtering in windows 98

how to use IP filtering in windows 98

A third party firewall would be the most practical solution.

Malir, you do not know enough about networking in general to be able to close the ports manually.
It requires programming a firewall yourself, and you are very far away from being able to do that.

Just accept that you will have to use a 3rd party software to do it.

Btw, this is not a 50 point question.
The difficulty of the solution would at least require 500 points.
Please, ask this question under programming, people will be able to help you there.