tezza Posted October 11, 2013 Share Posted October 11, 2013 (edited) I would like to share with you a new way I discovered to unlock the Last Known Good Configuration feature in Windows 8.1 and Windows 8 which Microsoft silently disabled. Let me explain why you might need it.Windows 8 and it successor, Windows 8.1, have more automatic diagnostics built-in than any previous version of Windows to inspect booting related issues and automatically repair them. 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. But sometimes, these features are an overkill.Suppose you installed a bad device driver inadvertently (e.g. some third-party driver to flash your phone) or some software driver and it started causing a BSOD while booting. 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. While the newly introduced features are useful for automating the restoration of the entire system, they can also take lots of time.In previous versions of Windows, there was an extremely useful feature called Last Known Good Configuration which allowed you to quickly to fix a broken registry hardware configuration to the one when Windows last booted properly. It was very handy in the situation I've described above. Last Known Good Configuration stored a copy of the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet key which contains information about all Windows services and drivers.Selecting Last Known Good Configuration at startup from F8 options did 2 things:- It restored the hardware configuration in the registry control set indicated by the LastKnownGood key instead of the default- It restored the device drivers too of the last working configuration, should a newly installed device driver make Windows unbootableIn favor of new additions, this wonderful feature was disabled in Windows 8.1 and Windows 8. The exciting news is that you can still enable it! Let's see how it can be done.Open the Registry editor (see how).Go to the following key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Configuration ManagerCreate a new DWORD value at the above key called BackupCount by right clicking in the right pane and choosing New -> DWORD value (32-bit) and set its value to 1 or 2, depending on the number of backups you wish to store in the registry. I recommend a value of 2. If the BackupCount value already exists, then simply double click it and set its value to 2.Now you must create a sub-key. Right click on the 'Configuration Manager' key in the left pane and select New -> Key called LastKnownGood. Then create a new DWORD value in the right pane called Enabled and set it to 1 (0 means disabled, 1 means enabled).Now the Last Known Good Configuration feature is enabled and will start backing up your HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet registry branch at every successful boot.How to access the Last Known Good Configuration in Windows 8.1To access the Last Known Good Configuration in Windows 8.1, run the following command at an elevated command prompt:BCDEdit /SET "{Current}" BootMenuPolicy LegacyThe above command will enable access to the regular legacy boot menu via the F8 key.Alternatively, you can also make the boot menu show on every boot with the following command:BCDEdit /SET "{bootmgr}" displaybootmenu yesNote: You can control all the hidden bcdedit options with my exclusive free portable tool, Boot UI Tunerhttp://winaero.com/blog/how-to-restore-the-last-known-good-configuration-feature-in-windows-8-1/ Edited October 11, 2013 by tezza Quote Link to comment Share on other sites More sharing options...
tezza Posted October 11, 2013 Author Share Posted October 11, 2013 (edited) if only this was posted yesterday....before my problems started! But i'm bookmarking this just incase it happins again! Thank you tezza very handy. You need to enable this reg setting before you have a problem :)( I have always used BootUI Tuner on win8/8.1 PC's, its an excellent tool and really handy.) Edited October 11, 2013 by tezza Quote Link to comment Share on other sites More sharing options...
geeteam Posted October 11, 2013 Share Posted October 11, 2013 'Thanks but i was using BootUI since the release of windows 8' Quote Link to comment Share on other sites More sharing options...
nanoman Posted October 11, 2013 Share Posted October 11, 2013 Thanks For The Share tezza ^_^ ;) Quote Link to comment Share on other sites More sharing options...
Reefa Posted October 11, 2013 Share Posted October 11, 2013 Thx for the share tezza.As @crazycanuk said bookmarked im sure this will be very handy oneday.. peace :) Quote Link to comment Share on other sites More sharing options...
eurobyn Posted October 12, 2013 Share Posted October 12, 2013 this is nice info and tool ,thank you Quote Link to comment Share on other sites More sharing options...
provision Posted October 14, 2013 Share Posted October 14, 2013 thanks for the info good stuff :) @tezza Quote Link to comment Share on other sites More sharing options...
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