Application Installation

The Auto PC Load program reads and executes the data stored in the CEI file generated by the CEI Builder. Auto PC Load performs the following tasks.

• Creates folders
• Moves files from the CEI file into the object store
• Adds registry information
• Installs speaker independent templates
• Adds speech phrases to list of phrases that can be trained and invokes training for any phrase not yet trained
• Invokes pre-entry and post-entry points from the installation DLL provided by the installation developer

The Auto PC Load application also checks the following to ensure proper installation:

• Error Conditions.

  Auto PC Load detects installation requests that require more memory than is currently available, and informs the user that the Auto PC Load cannot complete the installation if the installation requires too much memory. Memory requirements are calculated from the original list of files that need to be installed on the target device, excluding already installed components with the same version number as the component supplied in the CEI file.

  Auto PC Load also catches installation application errors and informs the user of these errors.

• Version numbers.

  Auto PC Load performs version checking on all PE (portable executable) file replacements. The version number of the replacement file must be greater than the version number of the original file for Auto PC Load to start the replacement process.

• Certification.

  Auto PC Load detects components that contain a Auto PC installation certificate. The Auto PC installation certificate indicates that the file may be a valid ROM replacement component. During installation, Auto PC Load validates the certificate and uses version checking to determine if Auto PC Load should replace the component. If all checks pass, Auto PC Load copies the replacement file to the RAM object store. After you reboot the Auto PC, the replacement file supercedes the old ROM component.

  Only Microsoft can distribute certified components. Certified components will be distributed as a part of subsequent SDK packages to allow third party developers access to the latest Auto PC components.

• Multiple Use Counting.

  When Auto PC Load installs a component, Auto PC Load increments the use count of the component. When Auto PC Load uninstalls a component, Auto PC Load decrements the use count. Auto PC Load uses a scheme that minimizes the number of use counts that must be stored while still ensuring that every installed file—not just every PE file—is subject to use counting.

• Backup.

  Auto PC Load prompts the user to perform a backup prior to installing or uninstalling any package.

  The backup operation is the same as the standard backup initiated in Setup.

• Existing Installations.

  If a CEI file is already installed on an Auto PC, one of the following occurs, depending on the version numbers of the two CEI files:

  • If the version number of the previously installed version of the CEI file is greater than the version number of the CEI file that user is trying to install, Auto PC Load displays a warning to the user that the user is trying to install an older version of the package and exits.
  • If the version numbers of the two CEI files are identical, Auto PC Load prompts the user to uninstall the package.
  • If the version number of the previously installed version of the CEI file is less than the version number of the CEI file that user is trying to install, Auto PC Load uses a special upgrade mode to install the new CEI file. The next section describes this special upgrade mode.
• Upgrading Installations.

  Auto PC Load supports upgrading an installed package (CEI). If Auto PC Load attempts to install a newer version of a previously installed package, Auto PC Load performs a special “upgrade” uninstall of the earlier package. Auto PC Load then performs a normal installation of the newer version. In this special "upgrade" mode, Auto PC Load does not install files or registry values marked as “Never replace” or “Leave Existing Value” in the earlier CEI. This mode leaves these files and registry values intact. If those same files and registry values are specified the same way in the newer CEI, those files and values remain when the new CEI is installed. An application developer should specify these flags only for files and registry values that contain user data. In this way, Auto PC Load preserves an application’s user settings and documents across a version upgrade.

• Speech Training.

  Auto PC Load makes interface calls to incorporate the information from a speaker independent template file into the speech engine. Auto PC Load removes the template during uninstall.

Custom Setup DLL

You can include custom setup DLLs in your installation. Two DLLs are supported, install and uninstall.

The install custom setup DLL exports the following entry points:

• install_init()
• install_exit()

The uninstall custom setup DLL exports the following entry points:

• uninstall_init()
• uninstall_exit()

Note If you provide the uninstall custom setup DLL, this DLL is saved along with the uninstall script in the \Windows\uninstall directory. The install custom setup DLL is never retained after installation is complete.