Just as a footnote to any request for help in situations like this.. our answers are verymuch a shotgun approach, and can be confusing to not only the poster but also many others, to avoid this when posting try including the following

1/ Please list your O/S and version.. perhaps even Service Pack's installed
2/ What A/V software you are running
3/ What Firewall do you have (Hardware, Software)
4/ May even help to give a quick list of your system spec's cpu, ram (see #1)

IF you are running windows a quick peek at your startup list is a good help.. if you have a version that has "msconfig" check the startup list there.. there are some good progs that can also help out here..

Check out the tutorials as well.. some great info here regarding some of these issues

Cheers