Method of recording TV (and input devices) on your computer?

We need more info to give a good answer. Is it a laptop or dekstop? What operating system (windows, linux, or mac)? There are lots of different options, from internal cards for you desktop to exteral devices for your laptop. To sum it up: you need a piece of hardware to encode an analog signal into digital a digital signal. Elgato makes some great hardware for Macs.

Laptop, so no tuner cards, windows is in the topics.

Oh sorry, I missed the Windows topic. I am not familiar with external encoders for that OS. Take a peak at Newegg’s list for TV tunes. I suggest getting a more expensive model that performs external Mpeg encoding. The cheaper models will still give you a good quality signal, but encoding on your laptop will chew up most of your processing power.