Dell Inspiron 8500 - Manual (Page 24)

Before you change any of the default display settings, make a note of the default settings for future reference.
If you choose a resolution or color palette that is higher than the display supports, the settings adjust automatically to the closest possible setting.
Microsoft® Windows® XP
1. Click the Start button and click Control Panel.
2. Under Pick a category, click Appearance and Themes.
3. Under Pick a task..., click the area you want to change, or under or pick a Control Panel icon, click Display.
4. Try different settings for Color quality and Screen resolution.