Changed wifi router, now ethernet doesnt connect - Win 8.1

I have a slightly different setup so I'm hoping somebody might have some suggestions on what I can try.

I have Comcast Xfinity Internet and a Motorola SB6121 model - have all worked great for years no problems.

I have the modem in my garage with a wifi router and a router for various rooms in my house. My home computer is in an office and previously I had a wired connection that worked great.

I changed wifi router to a new Netgear and the internet connection from the modem is working, the wifi is working, but my home computers ethernet connection will no longer connect...

Any thoughts on what to try other than powering off and on model / routers / computer which I have tried?

Mike

You can only have one router on your network. For extending coverage, you use Access Points

As for the Ethernet problem, go back and double check your connections to the router.

If you cascaded routers in what are called "Edge Routers". Changing your first router, without any changes on the others can be why you only have a connection to one router and not out to the Internet.

It is really easier to show someone what they did wrong, then explain on a forum.