Go this website.
Click on the blue button:
On the following page, click on the Agree and Download button:
Save the file when the popup appears:
When it’s finished downloading click on the GoogleEarthSetup.exe file in your Downloaded files list (hit Control J if you’re not sure where that is)
Click on Run if you get a security warning:
The program will now start downloading and installing the full package:
When it’s done, you’ll be told:
Click on close.
To open Google Earth, look in the Google folder of your Start Menu:
[...] Location: Installing Google Earth [...]
[...] Location: Installing Google Earth [...]