If you can not see the full image on your screen then you may have your resolution set to low. Screen resolution is easy to change and some course materials may require a specific setting for quality viewing.
Changing screen resolution in Windows XP:
Open Display in Control Panel or right-click on the desktop and choose properties
On the Settings tab, under Screen resolution, drag the slider, and then click Apply
When prompted to apply the settings, click OK. Your screen will turn black for a moment
Once your screen resolution changes, you have 15 seconds to confirm the change, click Yes to confirm the change; click No or do nothing to revert to your previous setting
Changing screen resolution in Mac OS X:
Open the System Preferences (either from the Dock or from the Apple menu)
Open the Displays Panel and choose the Display tab
On the left of the Displays tab you can select one of the Resolutions from the list. Higher resolutions allow you to see more "stuff". The commonly used settings are 800x600 and 1024x768 unless you have been requested to use a specific resolution.