National Geographic Magazine @ nationalgeographic.com

Pristine reefs, remnants from a golden age, polar bears at rest and play, all make perfect backdrops as this month's desktop wallpaper.

Week 1

Paradise Preserved
Anemonefish swarm a healthy Manra reef in the sunwashed wilderness of the Phoenix Islands.

Photograph by Paul Nicklen

Click your monitor size to download image:
- 15 inches (38 centimeters) or smaller
- 15 inches (38 centimeters) or larger

Week 2

Ancient Sentinel
Largest in a chain of earthen towers, a 45-foot-tall (14-meter-tall) lookout post in Xinjiang helped soldiers scan the western horizon beyond the edge of the Han Empire. At the first sign of marauders, they sent up smoke signals.

Photograph by Robert Clark

Click your monitor size to download image:
- 15 inches (38 centimeters) or smaller
- 15 inches (38 centimeters) or larger

Week 3

Sleeping Heap
Oblivious to the subzero cold, a big male polar bear slumbers on a bed of snow. Two layers of fur and thick fat act as superb insulation, helping polar bears retain virtually all their body heat.

Photograph by Norbert Rosing

Click your monitor size to download image:
- 15 inches (38 centimeters) or smaller
- 15 inches (38 centimeters) or larger

Week 4

Just Chillin'
With a swipe of his paw, a male polar bear brings down a branch and a load of snow from a willow shrub.

Photograph by Norbert Rosing

Click your monitor size to download image:
- 15 inches (38 centimeters) or smaller
- 15 inches (38 centimeters) or larger

For Windows 95 or Higher

1. Determine which size is appropriate for your monitor.

2. Click the size you wish to download.

3. After the image appears in your browser, click the right-hand button on your mouse.

4. On the menu that pops up, select SET AS WALLPAPER or SET AS BACKGROUND.

For Mac OS X

1. Determine which image size is appropriate for your monitor.

2. Click the size you wish to download.

3. After it appears in your browser, drag the image onto your desktop.

4. From the Apple menu select SYSTEM PREFERENCES.

5. Select DESKTOP.

6. In the pull-down menu marked "Collection," select CHOOSE FOLDER.

7. Locate desired image file and double-click it.

For Mac OS 9 or Lower

1. Determine which image size is appropriate for your monitor.

2. Click the size you wish to download.

3. After it appears in your browser, drag the image onto your desktop OR click and save the image to your desktop.

4. From the Apple Menu (at the top left of your screen) select CONTROL PANELS, then DESKTOP PICTURES or APPEARANCE. (If the new window reads APPEARANCE, select the tab that reads DESKTOP.)

5. If necessary, click REMOVE PICTURE to clear the current desktop picture.

6. Click SELECT PICTURE or PLACE PICTURE. A new window will pop up.

7. In the new window, use the pull-down menu at the top and select DESKTOP. Find the desired image in the file list and double-click it. The window will close.

8. In the APPEARANCE window, select SET DESKTOP.