Returning to the last known good configuration

Changes to the system configuration may keep the system from booting. If you suspect that boot problems are the result of a configuration change, you may be able to correct the problem by returning to a previous configuration. This method is simple and fast, and in some cases will correct boot problems in a Windows computer. There are slightly different procedures for Windows operating systems. This section includes procedures for each type of computers.

Any changes made to the system since the last time the configuration was saved are lost.

To return to a previous configuration

Restart the system.
Press <F8> during startup.

Select one of the following options:

Safe Mode	This option allows you to diagnose and fix system startup problems. For more information, see your Microsoft documentation.
Last Known Good Configuration	This option allows you to return to a previous saved configuration.