Installation manual

60 Installing Managed System Software on Microsoft Windows Operating Systems
In addition to the rollback of MSI Standard Actions, the Dell OpenManage
library also has the ability to undo commands listed in the INI file for each
application if a rollback occurs. All files that are modified by the Dell
OpenManage installation actions are restored to their original state if
a rollback occurs.
When the MSI engine is going through the installation sequence, it ignores
all actions that are scheduled as rollback actions. If a Custom Action,
MSI Standard Action, or a Dell OpenManage installation action fails, then a
rollback starts.
An installation cannot be rolled back once it is completed; transacted
installation is only intended as a safety net that protects the system during
an installation session. If you want to remove an installed application, you
should uninstall that application.
NOTE: Driver installation and removal is not executed as part of the installation
transaction and therefore cannot be rolled back if a fatal error occurs during
execution.
NOTE: Installations, uninstallations, and upgrades that you cancel during installer
cleanup, or after the installation transaction is completed, are not rolled back.
Failed Updates
MSI patches and updates provided by vendors must be applied to the original
vendor MSI packages provided. If you intentionally or accidentally repackage
an MSI package, or make changes to it directly, patches and updates may fail.
MSI packages must not be repackaged; doing so changes the feature structure
and Globally Unique Identifier (GUID), which break any provided patches or
updates. When it is necessary to make any changes to a vendor-provided MSI
package, use a .mst transform file.
NOTE: A GUID is 128-bit long, and the algorithm used to generate a GUID
guarantees unique GUID. The product GUID uniquely identifies the application. In
this case, the product GUID for Server Administrator is {DDA04AC3-F66B-47E0-
B189-6008EB1D80A2}.