Oh, I see, my bad Mike.
You need to revert everything back to DHCP (not too big o' deal) and then what you'd idealy like to do is setup what is called a "reservation" for an IP address that will be assigned to a static computer.
I'm not sure what it might be called on your linksys router tho... it might use another term other than "address reservation".
Another terminology that is really a different animal but serves the same purpose is setting up an "exclusion" on an ip address and then DHCP will not allow computers to get this IP when looking for an IP via DHCP, then you'd set the PC up with that address manually with the instruction I posted before about going into network settings > NIC card > TCP/IP > Properties > etc.
Give it a whirl, if anything you'll be just a little smarter about networking after all of it
