Each time you successfully start your computer, Windows saves any system-related settings to the Windows Registry. Some of the information that is written to the Registry is in regards to device drivers and services that are used by Windows.
The Last Known Good Configuration boot option uses Registry information and drivers saved at the last proper shutdown. Any system changes since the last proper shutdown are lost. Missing drivers or files necessary for operation of new devices will have to be replaced with proper versions. This is the next best thing to restoring the system to a prior system Restore Point and does not affect installed applications unless they involve device drivers.
Windows will not boot or function properly due to recent changes in hardware or system configuration.
Solution:
- Using Windows startup menu
- Restart your PC and press the F8 key at the end of the BIOS to access Windows' start menu.
- Select the Last Known Good Configuration option and let Windows start up.
- Log onto Windows if prompted.
- Reset any recent configuration changes, uninstall recently installed hardware or run System Restore to return the system to a working state.
When you choose to use the Last Known Good Configuration mode all of the settings contained within the HKLM\System\CurrentControlSet
Registry key will be restored to the last state when you’re computer booted up successfully. This will not modify any files, but it will be able to point the system back to older drivers, assuming that they are still accessible on the machine.