Restore Internet Use

Hello,

I am hoping for some assistance. I restored my Dad's old Dell Dimension B110 to factory settings as it was operating terribly and am now unable to connect him to the internet. The computer came with Internet Explorer and the Internet Explorer Icon is of course on the desktop, but will not work. It is from 2004. It is so old it has a "AOL 6 Months Free" Icon on the desk top and asked is I wanted dial-up connection when I restored it. How am I able to restore the internet. Thank you very much.