The Internet Explorer 9 offline installer supports numerous command-line options that can also help you to automate installation on computers that are already running Windows 7.
/help : Displays command-line help.
/passive : Runs the installer without any input from the user.
/quiet : Runs the installer without any input from the user, and without showing the user interface.
/update-no : Installs Internet Explorer 9 without checking for updates.
/no-default : Installs Internet Explorer 9 without making it the default web browser.
/closeprograms : Closes running programs automatically.
/recommendedsettings-no : Turns off the SmartScreen Filter and Compatibility View features.
/norestart : Installs Internet Explorer 9 without restarting the computer.
/forcerestart : Installs Internet Explorer 9 and always restarts after installation.
/log:folder : Creates a log file in the folder that is specified by Folder.
/x:folder : Extracts the contents of the installer in the folder that is specified by folder; used to extract the update package (MSU file) to add to a Windows 7 image or an MDT deployment share.
To learn more about piloting IE9 in Windows 7 visit TechNet.