closing ports

It really depends on what you are running on your network as to what ports need to be block. I would take a look at this link to find the port numbers for the apps that are accessed throught the internet if there are any.
http://www.iana.org/assignments/port-numbers
The first port i would block would be 139 and 137
these are your netbios ports if you are running a web or FTP server then you will need 80 and 21 open. It really depends on what apps are accessed through the net. The best practice is if the port is not being used to block all incoming traffic from the port. Most firewalls automatically block ports unless you specifically open them

It looks like you are running NT for your web server, and I would guess that you do have a firewall enabled (since ICMP packets are rejected).
Some more details on what problems you are experiencing will help determine a solution.

Good luck.

Here are some links to articles that may be helpful. This forst one is to a Network Computing article on securing desktops by blocking ports and more. (It's a 6 page article)

http://www.networkcomputing.com/1223/1223f4.html

This is a SANS Institute article on Applying Security to an Enterprise.

http://rr.sans.org/modeling/zachman.php

"An Embedded Firewall can give employees access to an internal server for specific
information, but blocking unnecessary ports and protocols..."

http://www.3com.com/other/pdfs/legacy/en_US/efw_SolBroch.pdf

The process of blocking unnecessary ports on Windows 2000 included in this article describing 3 Ways to Secure Your Windows NT/2000 Servers:

http://security.technow.com/articles/3.ways.secure.nt.2000.htm

A list in the following security article displays some common IP ports and services.

http://rr.sans.org/web/sec_IIS.php

"Hardening Windows 2000"

http://www.systemexperts.com/tutors/HardenW2K101.pdf

(REMOVE SPACES from the pasted URLs.)

Maxwell