How can you use a computer monitor as a tv? Can you?

with a TV tuner card yes, and some monitors have a HDMI plug in, but if you only have VGA or DVI cable input you'll need to either install a TV tuner card into the computer, or a external standalone unit. but honestly it's gonna cost around 20-50 for a cheap card, probably around 50-100 for a external unit. You can buy used TV's pretty cheap in the news paper, especially if your working with only a 17 inch monitor I wouldn't worry about it. Otherwise you can get LCD TV's 26 inch for as cheap as $350-400 shipped from newegg.com which you can use as a TV or a monitor that has every plug in support.

you can do that know but you have to go thru the cable tv box. The FCC just issued a mandate that cable companies make their details available to computer card makers so soon there should be cards that you can take your cable wire directly from the wall and into your pc. Then yes you can watch cable tv on your pc with no problems.

If you can take your computer down to 640x480, you can try connecting it to your TV. Many laptops actually include an "s-video" out for exactly this purpose. Depending on your laptop it may be treated as a mirror of your laptop display, or as a second monitor, or you may be able to switch between them. You will quickly see that the quality of the display is, likely, very very poor. If S-video is not an option, there are converter boxes available from places like Radio Shack that will take a standard VGA connector and turn it into a composite video signal that can be plugged into a TV with a composite input. In general this results in roughly the same poor quality computer display. Surprisingly, in both of those cases, video playback can actually look quite good. What I mean is that if you're using your TV as a computer monitor and to do typical things like reading email or surfing the web, you'll be quite disappointed. However if you are playing back a video - say playing a DVD in your computer and watching it on the monitor - it seems to be quite acceptable. My theory is that most DVDs and other videos are targeted at exactly the TV's resolution, and that, plus the fact that for video we're "used to" that resolution, our expectations for that type of display are simply met. Oh, and as to using it as a second monitor - to mirror what's going on on your primary computer screen: many laptops support using both the internal LCD screen and the VGA (or S-Video) output at the same time, so you may be able to simply hook it up. If you don't have that option, you'll need to get a splitter of some sort that will allow you to take your computer's monitor output and send it to two different devices: your regular computer screen, and a VGA converter box as I described above. Alternately you could purchase a video card that supports TV-out, or supports dual screens. Now, there is salvation on the horizon, but it'll require a new TV. Newer TV's are going digital, and many do, in fact, have digital (DVI) input - particularly those that are High Definition (HD) ready. In these cases you actually stand a chance of being able to connect your computer directly to the TV. The TV may not support the same higher resolutions that your computer monitor might, but they'll almost certainly support resolutions that are much more acceptable for computer usage. (All this is based on my own set of experiences some time ago attempting to do exactly what the questioner was asking. If there are particularly new or novel solutions to this problem that I've overlooked, I'd love to hear about them too. Just leave a comment below.)