|There are two different kinds of "wireless" internet.|
The first is provided by connecting a wireless router or accesspoint to a wired modem. Your laptop then needs a wireless network card in order to gain access.
This is the kind of wireless available at hotspots like Libraries & Restaurants, and used by most home users to give their cable/dsl broadband wireless connectivity.
The other kind of "Wireless" internet is accessed using a USB Broadband modem that connects to an ISP wirelessly via cellphone network. Any PC with an available USB port and suitable operating system can use this. It is usually very expensive with low download limits.
Since you did not give information on the make/model of your laptop ( Old is a comparative term and completely useless as a description) We can only guess as to it's equipment.
Goin' Fishin' (Some day)