The Windows Vista Snipping Tool allows you to capture a window, full screen, rectangular area, or a free-form selection.
When you attempt to capture an image of the Start menu or context menu, accessing the Snipping Tool causes the Start menu and context menu to close.
To workaround this behavior:
1. Start / Programs / Accessories / Snipping Tool, or select New if the tool is already open so it is in capture mode.
2. Press Cancel or minimize the Snipping Tool.
3. Open the Start menu or context menu that you wish to capture.
4. Press Ctrl + PrtScn to copy the window the screen to the clipboard. Since the Snipping Tool is in rectangular capture mode, you can select the portion of the screen that you desire.
NOTE: Selecting New and minimizing the tool allows you to capture another image.