Here's how to download the standalone installer for Google Earth:
1. Go to Google Earth's homepage and click on "Download Google Earth".
2. At the bottom of the page, there's a small message: "Customize your installation with advanced setup." Click on "advanced setup".
3. Disable this option: "Allow Google Earth to automatically install recommended updates."
4. Click on "Agree and download" and you'll get the offline installer. The direct download link for the Windows version is: http://dl.google.com/earth/client/advanced/current/GoogleEarthWin.exe.
The advanced setup page offers two other interesting options: installing Google Earth for all user accounts and the full setup for Google Earth 5.0.
Google Chrome should add a similar page that lets you download the standalone installer and a version that installs the software for all user accounts. This page still offers the standalone setup, but it's an old version. Right now, Google Pack is the only option to install Chrome for multiple user accounts.
{ Thanks, Brian. }