Cannot Change Display Setting to 640 X 480 or 256 Color

When you are using the slider on the Settings tab of the Display Properties dialog box to change the screen resolution, the slider will only go as low as 800 X 600. Also, the Color quality setting will not go lower than 16-bit.

640 X 480 resolution and 256 colors are not supported display settings for Windows XP.

NOTE: This workaround is not supported by Microsoft.

To work around this issue, follow these steps:

1. In the Display Properties dialog box, click the Settings tab.
2. Click the Advanced button.
3. Click the Adapter tab, and then click the List all modes button.
4. Select the resolution, color depth, and refresh rate that you want and click OK.

This behavior is by design.