Or maybe you installed an incorrect version of a particular driver which is not fully compatible. If a Blue screen error starts happening right after you did something like that, then you definitely know what broke your PC and would want to fix it quickly without restoring your whole system using System Restore, let alone Reset/Refresh.
some third-party driver to flash your phone) or some software driver and it started causing a BSOD while booting. Suppose you installed a bad device driver inadvertently (e.g. But sometimes, these features are an overkill. Startup repair often kicks in by itself when Windows fails to boot. Besides, there are features like Reset and Refresh which significantly make it easier to restore the system to a healthy state by automating the whole procedure.
HKLM is an abbreviation you’ll see often in discussions pertaining to the Windows registry, and it stands for HKEY_LOCAL_MACHINE and contains global settings regarding your PC. See Booting your PC into Last Known Good Configuration for directions on restoring your PC to a working copy of CurrentControlSet via CurrentControlSet002.
Booting your PC into Last Known Good Configurationĭirections on how to configure Windows to boot into Last Known Good Configuration have been moved to a separate article, as this detailed description of how Last Known Good Configuration operates underneath the hood contains advanced details, knowledge of which is not required to actually make use of LKGC. When Windows fails to start, it is possible to to request Windows boot into “Last Known Good Configuration.” Here, instead of pointing CurrentControlSet to CurrentControlSet001 (as is the default behavior), Windows will instead make SYSTEM\CurrentControlSet point to CurrentControlSet002 - which (since we used it before) we know is good and working. If changes made to CurrentControlSet end up causing Windows not to work properly, the configuration that was used last time for Windows is still available in the backed-up copy. This finally brings us to the topic of the day: Last Known Good Configuration. Any changes made to HKLM\SYSTEM\ CurrentControlSet are in actuality being made to CurrentControlSet001. CurrentControlSet is then “pointed” at CurrentControlSet001, to which it serves as a shortcut. When your computer first starts up, Windows copies HKLM\SYSTEM\ CurrentControlSet to HKLM\SYSTEM\ Clone. In reality, CurrentControlSet is actually a shortcut/pointer to one of CurrentControlSet001, CurrentControlSet002, or Clone. To protect against system errors and provide an easy recovery option, each time Windows is successfully booted, the old CurrentControlSet and all its contents is copied and set aside.
Inside HKLM\SYSTEM, all configurations and settings that have to do with your hardware, the drivers to communicate with that hardware, and system services are found in HKLM\ CurrentControlSet. The HKLM\SYSTEM registry hive, as mentioned above, contains most of the settings and configurations that Windows uses to determine what drivers to load, which settings to use, what policies are configured, etc. The Windows registry is split into 4 primary sections: HKEY_CURRENT_USER which stores settings related to the logged-in user account, HKLM\SAM 1 which stores information about Windows usernames and passwords, HKLM\SECURITY which contains settings related to the security configuration of your machine, and HKLM\SYSTEM which stores all global settings for your PC. Windows stores almost all of system-related configuration and settings in the Windows registry.