closing ports

Well considering there are 65+ thousand of them it is a bit hard to describe them all here. Here is a link that will give you some idea of what they are and what some of them are used for. (watchout for linewrap spaces, its long)

http://www.isi.edu/in-notes/iana/assignments/port-numbers

you might also want to go to http://grc.com and spend sometime there getting an idea of vulnerabilites etc.

as to closing them well it really depends on what your running and hard to say, basically you have to turn off the service that has in fact opened that port, OR install a firewall that enables you to control what gets in and what gets out.

Run the programs at grc.com and you should get some idea of what you can be doing.

This should get you started. :)

Locate the program called ZoneAlarm. After the install. Load each program. ZoneAlarm will pick up any port use and report it on it alarm screen. It will then ask if you wish to let the program run the port or block it.

Paul.