Internet DRivers Missing ?
Sounds like what you are missing is the NETWORK drivers for that machine. Was it connected to the internet using wireless, or an ethernet cable to your router/modem? Either way, you should be able to download them onto a flash drive and copy them to the Gateway.
To find out exactly what's missing, right-click on My Computer and select properties, then choose Hardware Manager, and expand the section with Network devices. That will tell you exactly what network hardware your machine has so you know what drivers you need. You may need to go direct to the device manufacturer's website to get the drivers as I have noticed that many big computer sellers, like Sony and Gateway, don't offer all of the required drivers for their machines in their support downloads section of their website.