I have a Dell Dimension XPS R450 Desktop, with MS Windows XP SP3, which I would like to connect to the internet by way of a Linksys Wi-Fi Router N300 Model E1200-NP. Can this be done? Will I need a Network Adapter from someone?
If this is the machine I believe it to be, you will need a network adapter PCI (not PCI-e) expansion card that contains an Ethernet port, or a wireless port. You should be able to select a card of either type for a reasonable price.
EDIT: Examples of the cards follow. You do not need to choose one of these as many vendors make cards of equivalent capability.