Acquisition: The Installer first installs the feature and then progresses through the actions specified in the sequence tables of the installation database. These actions query the installation database and generate a script that gives a step-by-step procedure for performing the installation.
Execution: The installer passes the information to a process with elevated privileges and runs the script.
Rollback: If an installation is unsuccessful, the installer restores the original state of the computer. When the installer processes the installation script, it simultaneously generates a rollback script. In addition to the rollback script, the installer saves a copy of every file it deletes during the installation. These files are kept in a hidden,system directory. Once the installation is complete, the rollback script and the saved files are deleted.