Edited by Chang Zhu
To capture screen image on a Windows system, use the key "Print Screen" (first row, next to Num Lock).
For some systems/keyboards you may need to hold down "Ctrl" + "Alt" + "Print Screen".
The screen image will be copied to the clipboard. Paste into an application such as
Powerpoint or Photoshop for editing.
Open the application Grab. Grab can be found in the fold Applications/Utilities.
Capture screen image using the command Capture/Screen or a portion of the screen
using Capture/Selection. The image will be opened as a tiff file.