Windows 7 offers you location specific Aero themes based on the language and location you pick during installation. Later, you may add other themes from different countries, available from your HDD location:
1. Open C:\Windows\Globalization\MCT with your File Explorer
At MCT folder, you will find a five additional MCT-XX subfolders, each for a different country themes
2. To add a more country specific themes, open “Theme” subfolder and double-click on file with .theme file extension (“AU.theme”, for example, to add Australian specific themes)
Wait for your “Control Panel – Personalization” to be opened, and select desired theme.