How do I connect to xbox live when my xbox is in the basement and my computer is upstairs?

I want to connect to Xbox live but my Xbox 360 is in the basement and my computer is upstairs so I cant directly hook it up to the router. Is there anything I can do or do I have to buy that $100 wireless thing?

if u want get a 50 foot ethernet cable and run it along the sides of ur walls to your computer

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