With a PC TV Card:
A TV card inserted into your PC may allow you to connect your system if the card has the proper connections (such as RF, A/V, S-Video, component, or Coaxial). However, we have found that the image quality is not as clear as it is on a TV, in most cases.
With a Direct Connection (RGB or DVI Cables):
Nintendo does not manufacture any cables to make an RGB or DVI connection. While other companies may manufacture wires that can make this possible, we are not able to recommend them, as they are not licensed by Nintendo.