Which operating system ? and what type of monitor ?
Click start control panel display desktop you can select a different desktop from the drop down list
or a browse button where you can select different picturesthis may vary depending on your operating system
also you can change the settings for more or less pixels or from the drop down list pick the appropriate level of color range or troubleshoot also select advanced then general dpi normal
size, larger size or custom settings
Always click APPLY after making any changes
Open Personalization by clicking the Start button, clicking Control Panel, clicking Appearance and Personalization, and then clicking Personalization.
Click Window Color and Appearance.
Under Window Color and Appearance, click the color you want, and then click OK.
If you see the Appearance Settings dialog box instead of the Window Color and Appearance
window, the theme might not be set to Windows Vista, the color scheme might not be set to Windows Aero, or the computer might not meet the minimum hardware requirements for running Windows Aero.
For more information, see Troubleshoot problems with Windows Aero
Create Menu tab right click in the top of screen (toolbar) you will see a number of toolbar options select the menu bar
This will add to your screen toolbar File Edit View Favorites Tools and Help select the View from the drop down list will be a Zoom with percentages % and text sizes largest to smallest and Full screen option