networking - How to setup Wi-Fi as the default Internet conenction and Ethernet as private network

My setup is like this:

• I have two routers (R1 and R2) at home.


• R1 is used as a private Ethernet network that connects all my personal
  devices, such as printer, external HDD, etc. It's not connected to the Internet.


• R2 is connected to the Internet and serves to other devices such as laptop, mobile devices, gaming console, TV, etc.


• My Windows 8 laptop is connected to both - R1 via Ethernet and R2 via Wi-Fi.

Now, I cannot access the Internet on this laptop. Windows gives preference to Ethernet and try to connect to the Internet using this. I want Windows to connect to the Internet using the R2 Wi-Fi connection.

Answer

In most cases, the last accepted DHCP offer wins, which will update your route, DNS and IP address. For example, if your Ethernet gets a DHCP offer from R1 later than the Wi-Fi device from R2, the default gateway will be R1 which means you can't access the Internet. So you can try to disable the Wi-Fi device and then enable it after Ethernet gets an IP address.