You could use the Snipping Tool in Windows 7 upwards.
Capture part or all of your PC screen, add notes, save the snip, or email it right from the Snipping Tool window. You can capture any of the following types of snips:
Free-form Snip. Draw a free-form shape around an object.
Rectangular Snip. Drag the cursor around an object to form a
Window Snip. Select a window, such as a browser window or dialog box,
that you want to capture.
Full-screen Snip. Capture the entire screen.
After you capture a snip, it's automatically copied to the Snipping Tool window. From there, you can annotate, save, or share the snip. The following procedures explain how to use Snipping Tool.
Capture a snip
In Snipping Tool, select the arrow next to the New button, choose the kind of snip you want, and then pick the area of your screen that you want to capture.
Capture a snip of a menu
After you open Snipping Tool, open the menu that you want a picture of. (For Windows 7, press Esc before opening the menu.)
Press Ctrl + PrtScn.
Select the arrow next to the New button, choose the kind of snip you want, and then pick the area of the screen that you want to capture.
Annotate a snip
After you capture a snip, you can write or draw on or around the snip by selecting the Pen button.
Save a snip
After you capture a snip, select the Save Snip button.
In the Save As box, enter a file name, location, and type, and then select Save.
Remove the URL
When you capture a snip from a browser window and save it as an HTML file, the URL appears below the snip. To prevent the URL from showing up:
In the Snipping Tool, select the Options button.
In the Snipping Tools Options box, clear the Include URL below snips (HTML only) check box, and select OK.
Share a snip
After you capture a snip, select the arrow next to the Send Snip button, and then select an option from the list.