You mentioned that you purchased “some hardware to hook” up the computer to a TV, and I’m not 100% sure if I know what you mean. From my experience, all I’ve ever needed to get the job done is the appropriate cable, i.e. either a VGA, DVI, or HDMI cable (a simple Google search on any of these will return enough images for you to know what each of these cables should look like). Have you tried simply circumventing this hardware device?

Assuming that the hardware device is not the issue, however, you may just not have tried the correct resolution. Depending on the age of the TV, you might have to try some resolutions that may seem rather odd, if not counter-intuitive. The standard resolution that any TV should be able to accept is 640×480 (also know as VGA), which is the native resolution of traditional NTSC broadcasts. Obviously, such a low resolution is pretty darn near useless in combination with a PC — at a minimum you’ll need 1024×768 for a decent computing experience. The next resolution that you might want to try is 1280 x 720, or 720p. Pretty much all TV sets labeled as HDTVs, regardless of age, will be able to handle this signal. Higher resolutions, however, such as 1920×1080, or 1080p, are more problematic. Processing and properly displaying so many pixels effectively has only been possible for a few years, and as such, older TVs will simply not have hardware powerful enough to handle such an input signal — they may either flat out refuse to display anything but a blank screen, or you might end up with a horribly distorted mess.

The important thing to remember here is that you are trying to display a image on a device that is used to resolutions that stem out of the television world, not the computing world. That is, you need to try TV resolutions, such as VGA, 720p, and 1080p, since those will have the highest chance of working.

Oh, and if you’re using a laptop, simply plugging in the cable won’t necessarily be enough (depending on the make and model). Most laptops require that you let the computer know that you wish for it to use a different, secondary, display. On most laptops this is easily accomplished; it’s usually a simple key combination. Try pressing the F4 key while holding down the FN key (the function key). It might have multiple settings that it cycles through so you might have to hit this combination more than once.

If you’re on a desktop, however, and you have a relatively modern graphics card from either nVidia or ATI, then there is usually a control panel that goes with the card. Look for this control panel in the Windows “Control Panel.” Most graphics cards nowadays will have dedicated settings meant to TV use, so you might want to give those a try…

Hope this helps!