Software & Apps Windows 25 25 people found this article helpful How to Start Windows 7 Using Last Known Good Configuration LKGC starts Windows with the last set of working files by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on June 15, 2020 Windows The Ultimate Laptop Buying Guide Tweet Share Email Last Known Good Configuration, or LKGC for short, is a way in which you can start Windows 7 if you're having trouble starting it normally. It loads the drivers and registry data that worked the last time you successfully started and then shut down your computer. The biggest caveat with Last Known Good Configuration is that it's only valuable if Windows 7 was working as you'd expect the last time you properly shut it down. So if you've started Windows, tried to fix a problem, and then shut it down again with the problem uncorrected, this guide won't help. So the most important advice we can give is to use LKGC as one of the very first troubleshooting steps for driver problems and issues like Blue Screens of Death. These directions are for Windows 7 and Vista. Last Known Good Configuration isn't available in Windows 10 or Windows 8, but there are other startup options you can read about at the bottom of this page. 01 of 05 Press the F8 Key at the Windows 7 Splash Screen To start Windows 7 using Last Known Good Configuration, press the F8 key over and over just as, or just before, the Windows 7 splash screen starts to load (i.e., keep pressing it while Windows starts). This will load the Advanced Boot Options menu. It's really easy to miss the small window of opportunity to press F8. If you see the Windows 7 animation begin then it's too late. If you don't press F8 in time, wait until the Windows 7 login screen appears and restart the computer from there. Do not log in. If you do, and then shut down Windows 7, you'll lose any benefit of using LKGC. 02 of 05 Choose Last Known Good Configuration Use the arrow keys on your keyboard to highlight Last Known Good Configuration (advanced), and then press Enter. 03 of 05 Wait for Windows 7 to Start Wait while Windows 7 starts, hopefully normally. It shouldn't take much longer than you're used to. Unlike starting Windows 7 in Safe Mode, there are no scary-looking lists of system files running down the screen as Windows starts with Last Known Good Configuration. Remember, all you're doing is rewinding driver and registry settings to those that worked the last time Windows 7 was shut down properly. 04 of 05 Login to Your Account Log in to the same Windows 7 account that you usually use. If Windows 7 wasn't starting at all, and you've reached this point, it's a good sign that Last Known Good Configuration is going to solve, or at least get you closer to solving, the problem you were having. If your problem didn't start until later on, you'll have to wait until the next step to see if LKGC did you any good. 05 of 05 Check to See If the Problem Is Solved At this point, Windows 7 has loaded "known good" driver and registry configuration data, so you'll now need to test to see if the problem went away. If Windows 7 wasn't booting whatsoever, congratulations, it looks like Last Known Good Configuration worked like a charm. Otherwise, you'll need to test to see if the problem you were having reoccurs. For example, if you experienced a BSOD when you entered the Control Panel, give it a try. If you tried updating a Windows 7 driver and your sound quit working, try it out now. If Last Known Good Configuration didn't fix the problem, trying it again won't be of much use. It's only good once since, unfortunately, Windows 7 doesn't store multiple configurations. In most cases, your next option is to use System Restore. We have an article on how to use System Restore to undo system changes in Windows if you need help. However, if you were following a troubleshooting guide specific to the problem you're having, your best option is to go back to that troubleshooting and continue as directed. LKGC in Windows 10 If you're not using Windows 7 or Vista, you might be wondering how to start Windows 10 or 8 using Last Known Good Configuration. While there is a similar startup menu with troubleshooting tools, it doesn't include the option to use LKGC. What you can do instead in Windows 10 or 8 is boot into Safe Mode, which is a startup type that loads basic drivers and is often a first step in troubleshooting startup issues. See How to Use Advanced Startup Options for details on everything you can do from this menu, and check out How to Access Advanced Startup Options in Windows 10 or 8 for help getting there. As of January 2020, Microsoft is no longer supporting Windows 7. We recommend upgrading to Windows 10 to continue receiving security updates and technical support.