It's surprising the number of questions I get about something as seemingly simple as screen captures. But really, it's not the most intuitive thing to do in Windows.
While the commands and tools haven't changed in years -- going back at least to Windows 98, and probably prior to that -- the process is neither obvious nor documented in a single place within Windows help.
So here's my tutorial for taking a screen shot.
First, get your screen ready for having its picture taken.
Generally speaking, the resolution (the number of pixels wide and high) of your screen is not very important. Keeping your screen resolution and window sizes consistent between screens is good practice, but beyond that it doesn't matter much.
Color depth is important and should be set as high as possible. On most modern systems this means setting the color to Highest (32 bit) in the display properties. In Windows Vista, you get to this setting by right-clicking the desktop, clicking Personalize, then clicking Display Settings.
If you are capturing a screen for use in print, such as MSDN Magazine or TechNet Magazine, you need to turn ClearType off. See my posting about ClearType on the MSDN Magazine blog for details.
If you are capturing a screen for use online, such as on a web site, ClearType can stay on.
I also like to turn off transparency in Windows Vista, just because it provides a cleaner border around windows without losing the other Aero visual cues. With transparency on, you may see other windows behind the object of your screenshot, and this may be distracting. This is covered in my ClearType post.
Enough talk. Time for action.
Open the application window or dialog box you want to capture. Can you resize the window? Try sizing it so that you show all of the relevant information, but not too much unused "white" space.
Now it's time to actually capture the screen. This is all you have to do:
Done. This captures only the active window to the clipboard. (Note that, if for some reason you wanted to capture your entire desktop, you could just press the PrtScn key.)
OK, so you've captured the window. Now what? Well, presumably you want to use it somewhere, so let's save the screen capture to a file. You don't need any fancy graphics software. Just use the accessories already provided in Windows.
Done. That's it. You've captured a screen shot that can be used almost anywhere.
That's pretty much all there is to taking a screen shot. To get the most out of your screens, here are a few additional suggestions:
If you can resize the window, I find that around 800 pixels across is a good size that shows enough screen real estate but is readable online or in print.
It's also a good idea to avoid displaying any personally identifying information in a screen capture. If you need names for people or companies, or maybe an address or phone number, contact your editor to see whether any guidelines are in place for these things. If you're writing for one of the magazines, we have lists of approved names, and using these up front saves a lot of effort retaking screen shots later.
Don't resize your screens. If your screens are going to be in a print article, the production staff can do any necessary resizing in a way that is best suited to the needs of our offset printing process.
Finally, don't convert your screens to PNG or JPEG format. JPEG is a lossy format that will create artifacts in the image. It looks lousy, and we'll just end up asking you to retake the screens. Likewise, don't think saving JPEGs as BMP files will fool us. Once you've lost data in the compression process, you can never get it back. Therefore, save your screens as BMPs from the start and keep those files. If we need JPEGs -- such as for a web version of an article -- it's trivial to create appropriate images from the source BMP files.