Any tips on how to comcast decryption HD channels?

I recently bought a 46" Sony KDL-46HX853 Fuul HD (1080p) SmartTV. Is there a way to decrypt HD channels in comcast? Can I also view the HD channels on my PC with AMD Radeon ROG ARES II dual HD 7970 6GB GDDR5? Any suggestions on how to comcast decryption HD?
