I use an HDHomeRun with my computer. It has two tuners which gives you the ability to view and record programming on your computer. The HDHomeRun connects to the computer using a network cable. There are also tuners that use a USB port.
Once you have the tuner, you will need software to view or record programming. Some tuners come with bundled software. The HDHomeRun does not. If you are lucky and are using Win 7 you already have Media Center which works well. If you have Win 8 Pro you have to purchase Media Center for $9.99 or $99.99 for other Win 8 versions from Microsoft.
Here's some links:
SiliconDust HDHomeRunMedia Center AddOn
