When you run the executable file for the package, its contents are extracted into a temporary extraction directory. The location of that directory can be randomly generated by the package installer, or you can specify it as part of a command-line option. If you do not specify a path, the package installer determines which drive on the local fixed disks has the most disk space. It then uses a Windows application programming interface (API) to generate a random name for the extraction directory and places the directory at the root of the drive..
Analysis and Inventory
The software update installation begins from the extraction directory that was just described. The Update.inf configuration file that is a part of the package installer includes the installation logic and registry changes that are required to install the software update. The package installer identifies which files to install and examines the currently installed versions of those files. If the current version is the same as or newer than the version being installed, the package installer does not update the file. In rare cases where the version numbers are identical, but the file hashes are different, the package installer updates the file.
Before any changes are made to the files or the registry, the package installer archives in an uninstall directory a copy of the files that already exist on the system. (For more information about removing software updates, see Removing Software Updates later in this document.) The uninstall directory also contains spuninst.exe, an executable file that will remove the update, and Spuninst.inf, a configuration file that includes the logic and registry changes needed to direct the removal of the software update.
When you install any software update, entries are added to the registry that document the installation process. These entries include details concerning which files have been installed. Two registry locations are written when a software update is installed. These are commonly referred to as the Updates and Add or Remove Programs keys. The Updates key contains details about all Microsoft software updates. The Add or Remove Programs key contains information about Microsoft software updates that are displayed in Add or Remove Programs.
Contents of the Internet Explorer 7 software Update Package
Any software update package includes the installer file (Update.exe), supporting files, and the “payload”--the file or files that make up the actual software update. This section discusses the files and directory structure of a software update package.
This section describes the core files and the supporting files that are included in the package installer which is nothing but the Internet Explorer 7 installation package.
Core Package Installer Files
These files are part of the core package installer and change only when a new version of the package installer is released. These files do not change across packages that are built with the same version of the package installer.
When the Internet Explorer 7 is installed the files are saved in the following directories and during uninstallation these files will be removed from the same locations: