How to get internet

Hello,

Hello,
I am having a problam with the internat explorer on my computer. There is a connection as msn messenger works but no matter what I try I cant seem to get the internet. when I try to look at a page I just get "internet explorer cannot display the webpage". I then click diagnose copnnection problems and it tells me that
" windows cannot connect to the in internet using HTTP, HTTPS or FTP, this is probably caused by firewall settings on ur computer.
check firewall settings for the http port 80,https port 443 and ftp port 21"
i cant seem to find out how to check these settings.... can anyone help???
Thankyou!! xx