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Installer.Rollback Method

When overridden in a derived class, restores the pre-installation state of the computer.

Namespace: System.Configuration.Install
Assembly: System.Configuration.Install (in system.configuration.install.dll)

public virtual void Rollback (
	IDictionary savedState
public void Rollback (
	IDictionary savedState
public function Rollback (
	savedState : IDictionary



An IDictionary that contains the pre-installation state of the computer.

Exception typeCondition


The savedState parameter is a null reference (Nothing in Visual Basic).


The saved-state IDictionary might have been corrupted.


An exception occurred during the Rollback phase of the installation. This exception is ignored and the rollback continues. However, the computer might not be fully reverted to its initial state after the rollback completes.

Notes to Inheritors When you override the Rollback method in a derived class, be sure to call the base class's Rollback method first in your derived method. A rollback operation restores the computer to the state it was in before the installations occurred. The Rollback method is called if the Install method of this instance of Installer, or any installer in the installer collection, fail to run correctly. Any exceptions generated by calling the Rollback methods of the installers in the installer collection are ignored and the rollback of the other installers continues.

The following example demonstrates the Rollback method of Installer. The Rollback method is overridden in the derived class of Installer. An exception is generated to force an installation rollback.

// Override 'Rollback' method of Installer class.
public override void Rollback( IDictionary mySavedState )
   base.Rollback( mySavedState );
   Console.WriteLine( "The Rollback method of 'MyInstallerSample'" +
                     " has been called" );

// Override 'Rollback' method of Installer class.
public void Rollback(IDictionary mySavedState)
    Console.WriteLine("The Rollback method of 'MyInstallerSample'" 
        + " has been called");

  • Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see .

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0