Here is a short clip I put together that will walk you through setting up Chromecast on your pc. Here are my specs:
PC: Windows 8 – 64 Bit with Chrome browser. Built in WiFi capabilities
Router: ATT DSL Router
TV: Samsung 40″ HDTV (don’t remember model.. bought in 2007). Consists of 3 HDMI ports and 1 USB
Chromecast installer file: download here or download directly from google.