Just to be sure I understand.. you want to run an ethernet cable from your Xbox 360 to a wireless router which will be connected wirelessly to another wireless router which is connected to the internent?

This will work.. it is called a wireless bridge configuration..

Not every wireless router will work in this way.. you would need to do a little research on your particular router to figure out how to configure it..

Also, every Xbox (original and 360) has a wired ethernet port.. on the 360 its on the back next to the USB port near the AV connector..

Good luck..

There is an ethernet port on the back of the 360.

If you want to connect your 360 to your wireless router upstairs without using any cables, you need to get the Wi-Fi adapter. If you don’t want to spend the money to get a Wi-Fi adapter, you can run an ethernet cable from your 360 to the router.