Microsoft includes a “geographic” theme with every copy of Windows 7. American Windows 7 users, for example, can right-click on the desktop, choose “Personalize” and choose the “United States” theme, which includes several National Geographic-style wallpapers of some of America’s most majestic sites. Likewise, British users can choose the “United Kingdom” theme, and Australian users can choose the “Australia” theme.
Somehow or the other, Windows 7 is able to determine which country you’re in, and will only show that region’s theme by default in the “Personalize” UI. However, the rest of the themes are actually installed with every copy of Windows 7, and with one quick tweak you can use any theme you like:
1) In a Windows Explorer window, type or paste the following text, then press enter:
%WinDir%\Globalization\MCT
2) You will see several folders in the Explorer window. Click on “MCT-AU” for Australia, “MCT-CA” for Canada, “MCT-GB” for the UK , “MCT-US” for the United States, or “MCT-ZA” for South Africa.
3) Inside each country’s folder will be several folders. Click on the “Theme” folder, then click on the .theme file inside that folder to apply.