Setup of Home Network with Two Routers

[eiamjbj]

I have an old brick home that is very narrow, but has five levels. The Internet comes into our house on the first floor and I have the wireless router provided by the ISP on the first level. Previously I purchased a Linksys E4200 wireless router, but due to incompatibility directly with the ISP, I use their wireless router and my Linksys is not being used at all. I have purchased a Linksys Extender and it has helped get a better signal to the 3rd floor, but with the way the house is built, I'm lucky if I get a signal on the 5th floor. My question is this ... the previous owner ran Cat6 cables to each floor and I would like to have one network ... can I plug the Cat6 into my Linksys E4200 on the 5th floor to use the same network? In addition, can I make it so that there is a common wireless network that exchanges the device to the best signal as I go from one floor to another (i.e. I don't have to switch between the wireless networks)?
I would appreciate your assistance, but would kindly ask for as detailed instructions as possible as I'm relatively new to networking. Thanks for your help.

[Zachary]

You could connect the cable from the 1td router to the 2nd router via one of the LAN ports - do not use the WAN port. Then configure the 2nd router to not use DHCP. This should make the 2nd router act the same as a switch. The cable you need should be a crossover cable not a regular patch cable, if you are connecting router LAN port to router LAN port.