Learn how to connect and configure a second monitor to any PC laptop or desktop computer.
Why go dual-screen?
Around the CNET office, more and more people are using a two-monitor setup. It used to be a kind of luxury for data professionals -- people with lots of spreadsheets and documents that needed to be open side-by-side. But these days, with more people ditching desktops for laptops, hooking up an extra monitor is just a way to reclaim the screen real estate you lost by going mobile.
Now, maybe you considered a two-monitor setup years ago and got turned off by the idea of installing video cards and adapters. Those days are gone. With any reasonably new computer, you should be able to make this work with just a monitor cable, and a few minutes.
Mac users should check out the Mac version of this tutorial.
Let's start off with a Windows 7 laptop. This one's from Toshiba and it's a bit of a best case scenario. You get two ports on the side here, one for VGA and one for HDMI. Both options have their advantages.
HDMI (shown right) is the latest standard and delivers digital audio, video, and data in a single cable. Sometimes you'll get a full-size HDMI like the one used on the Toshiba laptop in the previous slide, but in many cases you'll find a Mini- or Micro-HDMI output that may require an inexpensive cable.
A DVI connection (shown left) is almost as ubiquitous as VGA. It is a digital video connection, although it has some analog legacy characteristics that allow it to be adapted for use with VGA in a pinch. It can also be adapted for HDMI, as shown with this inexpensive cable.
Does HDMI provide better video quality than VGA or DVI? Not necessarily. According to CNET's Eric Franklin, so long as both the monitor and the computer it's connected to are reasonably modern, the image quality over VGA or DVI is virtually indistinguishable from HDMI.
If you have the option, though, we'd recommend going with HDMI as the best-case solution for PCs. It offers the most compact connection and delivers the broadest range of data (audio, video, and data).
Now, what about a Windows desktop. Here's a recent one from Gateway, and on the back you'll see monitor connections for DVI and HDMI. One will need to be used for your main display, while the other is connected to your second monitor. It doesn't matter which port gets connected to which display, but chances are that your older monitor will lack HDMI, while a newer monitor will be able to accommodate an HDMI connection.
If all you see back here is a single monitor connection, you could spend some money on a video card or even a USB adapter. If it were me, though, I'd take it as a sign that I need to update my computer.
Most modern monitors will have at least one HDMI connection, as well as at least one VGA input and a DVI connection. If your monitor only supports DVI, an HDMI-to-DVI adapter should only set you back about $6.
Whichever port you choose to connect to, be sure to use the monitor's on-screen menu to designate it as your source input.
Next, go to the drop-down menu for multiple displays and select "Extend these displays." Then, hit apply. This will stretch your desktop across both displays and activate your monitor if it's not already. If the monitor is on but looks stretched out, too big, or too small, select the display up here at the top and fiddle with the display resolution until you find the sweet spot.
If the screen on your second monitor still looks a little off somehow, try adjusting the settings directly using the display's on-screen menu. Sometimes you'll find an "automatic" or "reset" function that will knock some sense into things.
You'll also notice a setting here for Orientation. If your monitor supports it, you can spin it on its side and set the orientation to 90 degrees. Some people like this setup for viewing documents or Web sites. It's not for everyone, but it's an option.