Is it possible to connect 2 routers together?

My friend has 1 computer in his house and 2 computers in his office in abuilding behind his house. The distance is too great for a wireless router to cover. He did run a single Cat5 between the 2 buildings and wants to have a wireless router in his house so his kids can use computers in the house wirelessly and hard wire the computer in his wife's office. So, to hardwire the 2 computers in his office, could he use the Cat5 wire to connect a second router in his office to service the other 2 computers?

Thanks in advance for any help!

Absolutely, you could actually disable NAT on the regular router turning into basically a switch.

Two routers is overkill for this type of setup. You don't want any kinds of conflicts. Especially since there probably isn't any type of managed networking devices like a server involved.

Just use a switch in the office. There will be a lot less setup, hassle, and cost involved. A gigabit switch would be nice, but don't bother for the costs where the cable is cat5.

he just needs the router he has now and a network switch.
he plugs his cat five into the router, and the other end into his switch.
from the switch he runs to his hard wired computers, and then you hook a wireless access point up to the switch as well. the router will supply all the ip addresses by DHCP.