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If you cannot run a cable between your TV and your Internet router, then you will need the Sharp Wireless Adapter. This should have been supplied with the TV. it is a small unit with a USB connector on one end - it looks like a 'USB memory stick'. Once you have located that and plugged it into one of the USB connectors on the side of the TV, you should be able to go to the internet setup.
Press MENU, then select 'Initial Setup', then 'Internet Settings', then 'Communications Setup', then 'Connection Type' and select Wireless.
Follow the on-screen instructions and you should be able to connect to the Internet.
Once you are connected to the Internet, you can press the 'apps' button on the remote, just to the left of the Menu button. Select Netflix and follow the on-screen instructions and you should be good to go!
If this helps, please don't forget to click the 'accept' button.