Symantec WINDOWS INSTALLER EDITOR 7.0 SP2 - REFERENCE FOR WISE INSTALLATION EXPRESS V1.0 Installation Manual page 483

Windows Installer Editor Reference
run asynchronously. See Rollback Custom Actions in the Windows Installer SDK
Help.
Commit only
Select this if the action should be executed later, during installation of the commit
script, which is invoked upon successful completion of the installation script.
Commit actions run in deferred execution mode. See Commit Custom Actions in the
Windows Installer SDK Help.
Deferred Execution - System Context
If execution of the custom action requires elevated privileges, set this option. You
must also set AlwaysInstallElevated keys in the registry. See AlwaysInstallElevated
in the Windows Installer SDK Help. This makes the custom action run as though it
were logged on as a system account, similar to the way services can log on as a
system account.
Note
User context and system context are relevant only on locked-down computers.
Actions run in system context are run with elevated privileges by the Windows
Installer service. Actions run in user context are run with the current user's
privileges.
Processing
The main installation thread can control the custom action thread in different ways.
Options in this drop-down list determine how the custom action thread is controlled. See
Custom Action Return Processing Options and Synchronous and Asynchronous Custom
Actions in the Windows Installer SDK Help.
The Processing options are not available if the custom action type is Set Property or Set
Directory and are limited to synchronous for Install MSI custom actions.
Synchronous
Run the custom action synchronously to the main installation thread. Windows
Installer waits for the custom action to complete before continuing the main
installation. The exit code of the custom action must be 0 to indicate success. Use
this method for Windows Installer to wait for the success of the action before
continuing.
Synchronous, Ignore exit code
Run the custom action synchronously to the main installation thread. Windows
Installer waits for the custom action to complete before continuing the main
installation. Use this option if success of the action is unnecessary to continue with
the installation. The exit code of the custom action is ignored.
Asynch, Wait at end of sequence
Run the custom action asynchronously to the main installation thread. Windows
Installer runs the custom action simultaneously with the main installation. At the
end of the script, Windows Installer waits for the exit code from the custom action
before continuing. Use this if the installation is not dependent on completion of this
action, but you want to check the exit code. This option is not available for Install
MSI custom actions or if you selected Rollback Only in the In-Script Options list
above.
Asynch, No wait
Run the custom action asynchronously to the main installation thread. This means
that Windows Installer runs the custom action simultaneously with the main
installation. Windows Installer does not wait for completion of the custom action and
Custom Action Reference
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