Windows 10 KB4103721 bugs
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Microsoft yesterday released the cumulative updates for Windows 10 version 1803 and it appears to be causing a number of issues on some systems. Windows 10 KB4103721 bricks PCs and the installation results in a black screen on a number of systems. KB4103721 is the first patch for Windows 10 April 2018 Update and it was supposed to fix all the reported issues.

A number of users on Microsoft’s Community forums reported that there’s a problem with KB4103721. The Windows 10 KB4103721 is causing black screen and the system fails to boot. The only workaround which works for most of the users is to restore the system to the previous version of Windows 10.

While the first cumulative update for Windows 10 April 2018 Update (version 1803) includes bug fixes for the reported issues, it appears that there’s a bug in KB4103721 which is bricking PCs and preventing them from booting. It is, however, worth noting that not all systems are impacted.

There’s indeed a problem with this cumulative but it’s hard to determine a fix or the pattern at this point. In most of the cases, restoring the PC to the previous version of Windows helps and the PC finally boots to the login screen.

While several users have confirmed the bug on Microsoft’s Community forums, the software giant hasn’t acknowledged the installation issues yet.

Recover PC from the black screen after installing Windows 10 KB4103721

While the official workaround is not available at the moment, most of the users have managed to fix the installation issues by restoring the system to a previous point or downgrading to Windows 10 Fall Creators Update (version 1709).

You can only restore your PC to the previous version of Windows if you haven’t touched the windows.old and $windows.~bt folders after the upgrade.

The recovery process basically takes your PC back to an earlier point in time. Microsoft says that it is generated every time you install a new Windows update or driver. While restoring won’t affect your personal files, but the process will remove the apps, divers, and updates that you installed after the restore point was made.

To restore your system, you may need to enter the Advanced Startup. To enter Advanced startup and fix the installation issues, do the following:

  • Hit F11 as soon as the computer powers on. This can get you to the Advanced Startup Options menu, but it also depends on the manufacturer. The PC should also boot to Advanced Startup after several failed boot attempts.
  • In Advanced options, click “Go back to the previous build”.
  • (Or System Restore if nothing works).

Of course, the above method only works if the restore point is available. In case a restore point isn’t available, you’ll have to boot into Safe Mode and manually remove the update from the system. Here’s how you can boot into safe mode and uninstall the botched update.

  • Boot into Advanced Startup menu (Choose an option screen).
  • Select Troubleshoot > Advanced options > Startup Settings > Restart.
  • Select 5 or F5 for Safe Mode with Networking.
  • Log into Safe Mode.
  • Go to Settings > Update & Security > Windows Update > View update history > Uninstall updates.
  • Select KB4103721 and remove the update.
  • Reboot your PC, and it will finally boot as the update has been uninstalled.

You can also create a bootable USB drive on your second PC and clean install Windows 10 April 2018 Update.

As noted above, Microsoft is yet to acknowledge issues with this cumulative update. We’ll be keeping an eye on the forums and update the article when the official workaround is available.

  • p1553d 0ff

    Latest cumulative update for Windows 10 version 1803 (KB4103721) does not complete – gets stuck at reboot phase. Both my PC and laptop are stuck in reboot phase! Absolute garbage from Microsoft – update after update with fix after alleged fix and things just get worse! I managed to restore my PC to a point before this stupid update and it worked but my laptop simply won’t allow me to do anything and doesn’t enter the “attempting to repair” screen it simply sits there with the neverending loading wheel going round and round and does nothing! Thanks for that Microsoft. You have wasted my entire morning trying to sort this sh*t out. I spend more time updating and trying to get your cr*p to work than I do getting any work done. Enough of this BS – time you tested and rolled out a finished product instead of relying on the end user to debug it for you.

    • 69na96

      Same thing here. Reboots couple of times and fails to install update.

      • p1553d 0ff

        Managed to download a Windows 10 bootable USB file ( that enabled me to boot into the Advanced Repair screen on my laptop – restored back to a point before the latest cumulative update but as soon as the laptop reboots I’m back to square one with a neverending boot process! The cumulative update remains on the “View Update History” list with the status “Requires a restart to finish installing” – then the entire endless reboot cycle starts again. Microsoft there HAS to be a solution to this nonsense. How can that pending update be removed from the list of updates completely until such time as you lot come up with a fix for this mess you have created?

        • Mayank Parmar

          There are a couple of ways to block Windows Update completely, I am writing a story on it.

          For now, just turn on battery saver.

          • Tone

            When you go in to control panel – windows update go to advanced options at the bottom – then toggle pause updates. This will stop the update reinstalling until there is a fix hopefully

  • Bojan Malinovic

    Both laptop and PC suffers from same black screen after instaling this KB. I found other solution. Boot to safe mode, then system will undo changes and you will be able to boot normaly to system.

    • FrankVVV

      Well, I couldn’t get it to boot into safe mode. I tried everything. The only solution was to reset Windows. Now I have to download and reinstall 650 GB of programs again. But the worst part is: Windows want to install the update. I do not dare to reboot my PC.

      • Bojan Malinovic

        Old safe mode menu is disabled by default…you need to enable it first with rescue usb and then it works.

        • FrankVVV

          Yeah, I did not have that.

          • Александр Смеляков

            Nah, just turn off your pc several times on windows boot

  • Eddie

    KB4103721 is causing a whole plethora of remote users and 3rd party consultants to not be able to connect to our RemoteAPP server anymore. They are getting this message:

    An Authentication Error has occurred.
    The function requested is not supported.

    Remote computer:
    This could be due to CredSSP encryption Oracle remediation.

    I’m having clients uninstall this update to fix the issue, but ultimately I will have to patch our Gateway server in a maintenance window, hopefully it doesn’t break other things.

    • disqus_DDEkcLuNfY

      yep, i’ve been running around all day uninstalling this one. i’m wondering when windows will try installing it again.

  • Mister Fantastic

    1. Right click on start.
    2. Click run.
    3. Type msconfig
    4. Click the “Services” tab.
    5. Uncheck the “Advanced System Care 11” service.
    6. Click ok.
    7. Click “restart your computer”.
    8. Update KB4103721 as normal. re-enable the service is you want.

    • SpasilliumNexus

      Kind of impossible to right click on start when THE ENTIRE DESKTOP DOES NOT SHOW UP, INCLUDING THE TASKBAR…

      • Mister Fantastic

        1. Calm down.
        2. Power on your PC. Then just as it’s starting (just as the circle animation begins) press the power key (or reset). Power it back on.
        3. Do this 3 times. Windows will then boot into the recovery console. You will see the words “Preparing Automatic repair” if you’ve done this correctly.
        4. You will see a screen that says “Automatic repair”.
        5. Press the “Advanced options” button.
        6 .Press Troubleshoot.
        7. Press Advanced Options.
        8. Click “See more recovery options”
        9. Click “Startup Settings”
        10. Click “Restart”
        11. Press F4 or the number 4 to enable Safe Mode.
        12. Windows will now boot into Safe mode and AUTOMATICALLY uninstall KB4103721. Depending on how many patches you’ve installed along with KB4103721 you may have to do this procedure more than once to get to that patch so safe mode will uninstall it.
        13. You’re welcome.

        I understand your frustration but I don’t work for Microsoft. I’m just a guy here to help. Yelling at me doesn’t make me WANT to help you.

        • Александр Смеляков

          Advanced System Care 11 is not installed on my system at all. The update still fails

          • Mister Fantastic

            Then it’s some other 3rd party software interfering with the update.

    • Mark Hansen

      Thank you! How did you stumble upon this service as being the culprit?

      • Mister Fantastic

        I started turning off 3rd party software as I wanted to prove to Microsoft that nothing I had installed was the culprit. But…I was wrong. Ha ha! Fortunately it was the first one I tried as it was at the top.

        • Mark Hansen

          Must be a significant number of folks with ASC installed…I had unplugged all USB items, disabled the security suite and shut down everything on the taskbar. I will be prepared for next month, although I hope IoBit has an update to sort things out.

    • Geoff Mulholland

      Thank you so much for this ! This worked for me.

      Windows updates are now up to date including KB4103721.

      I have since re-enabled the Advanced System Care 11 service, run a Scan, Fix and restarted with no problems.

      • Mister Fantastic

        You’re welcome.

    • ♔KingTodd♔

      Yea, i was up till 5am dealing with this crap.
      finally figured out it was ASC11, and my problem was solved.
      (after ENDLESS reboots into safe mode to fix the issue)

      BUT, i can’t get Update KB4103721 to install still, i get to the point after restart where its counting up, then once it hits 96%, it says failed and then restarts to remove itself.

      Even went to the the main site, to download the update manually.
      (Guess this update is completely broken??)

    • Reiza P. Riyadhi

      I was unchecked ASC 11 service but in my case it’s not resolving the issue, it might be another service cause this problem.
      Unfortunately I still have no clue what is it, avoiding this update still better solution for me now

    • pege63

      Thanks Mister Fantastic you are greate m8.

    • p1553d 0ff

      Seriously? Wow – I had to eventually resort to a PC reset and then install all my programs again – such a pain and so time consuming. Now my PC is back on 1709 and updated everything overnight – checked this morning and feature update 1803 is now downloading. Will allow it to install then switch off ASC11 as you described and then see if the evil KB4103721 will install and reboot successfully. Much appreciated for the work around – guess that is the down side to using 3rd party Apps?

    • Compulsive Learner

      Thanks Mister, you ARE fantastic!!!!

  • Sean Cullinan

    This happened to me. Returned home last night to a computer with a black screen. When I moved the mouse I had the spinning circle cursor. Let it run like that all night and nothing changed. This morning I tried a system restore. I did this by interrupting boot up 3 times with a hard power off it will go into repair mode which had a system restore option. The system restore failed and the problem persisted. I then went into safe mode (again using the interrupt boot method 3 times) and system restore popped up. I was able to successfully run this system restore and my computer worked (without this update) just fine. I then tried the update again and it failed again so it is definitely the update and an incompatibility with my PC. My repair method worked the second time and I’m up and running today with Windows Update paused for a month. Hopefully MS will fix this!

    • p1553d 0ff

      Do you have Advanced System Care 11 installed and running? If you can restore back to previous build (1709) then it turns out by stopping the ASC11 service via run>msconfig>services>uncheck Advanced System Care – reboot your machine and proceed with the update to version 1803 and the evil cumulative update KB4103271 your system will reboot and then you can turn the ASC11 service back on. Worked a treat for me on my laptop and on my PC but only after I was forced into a PC Reset which meant all software had to be reloaded – very painful and time consuming. Hope this helps.

  • Woody

    If the April 2018 update created a windows.old folder, I may be OK. If not, looks like I’m starting fresh.

    • Mayank Parmar

      Yep, your PC is good in shape. The windows.old folder would be there.

  • Mark Hansen

    This is highly annoying. I found that by booting into safe mode several times, the update was rolled back after two boots into safe mode. Then, once in safe mode, a restart will get you into windows. I then hid the update and we’ll see what next month brings. It seems as though the video driver never loads. Update: Mr. Fantastic has the fix below…worked like a charm!

  • Alexander M

    This happend to me aswell BUT I got a workaround. (Dell XPS15 9560)
    Enter safeboot mode by pressing F8 repeatedly times directly after starting the computer.
    Let it enter safeboot and you will see:
    Failure configuring updates. Reverting changes. Do not turn off your computer
    Login and shutdown the PC and then start it normally and it will work.

    Now dont go to Windows Update and search for updates until this is fixed.
    Enjoy :)

    • Mark Hansen

      Alexander, do you have Advanced System Care installed? If so, see Mr. Fantastic’s post below…worked great!

    • Reiza P. Riyadhi

      Look at your GeForce Experience, there is driver update for your gpu, update it and then updating windows, it’s resolved the issue

  • Jeremy

    Just found another possible solution – for those that have only Windows Defender running (or maybe any other anti virus applications) I was able to get the update installed, disabled Defender BEFORE the restart and it was able to complete the install and Windows loads as normal.

    Not sure what’ll happen on the next phase of Windows updates, but currently no issues to report.

    • ♔KingTodd♔

      Can i get the instructions on what you did(where you went to do so).
      seems a little different on disabling Windows defender then i remember.
      (only one i use for virus protection)

      My problem is, Once the update installs and reboots after installing 30%.
      Then on the Restart, it hits 96% then says “we couldn’t complete the updates undoing changes “, the preceeds to reboot and undo the changes.

      can’t get it to install…

      • Jeremy

        I went into settings -> update and security -> Windows Security -> Open Windows Defender Security Center -> Virus and threat protection -> Virus and threat protection settings -> Turned off real time and cloud.

        This of course was after the update got installed, but before I rebooted the PC to finalize the installation.

        • ♔KingTodd♔

          Yea, sadly.

          i still can’t get it past 96% before it says “we couldn’t complete the updates undoing changes “, then proceeds to reboot and undo the changes.

          Getting this error code in the option now:

  • Dorientje Woller

    Same issue here, solved the issue by updating my Bios, coz I had the weird issue that my Ryzen system was no longer retaining the memory settings and reverted to the base ones after this Windows update. With the update of my Bios, I am able to set the correct settings of my memory and save them without hick ups.

  • datuan007

    Thanks Mister Fantastic !

  • pege63

    I cant even restore the system to the previous version of Windows 10, its says there is previous version. I must restore from a backup point and that sux.

  • Marcin Pudełko

    On some multi Gpu systems like Samsung rc710 workaround is to remove display device and gpu in device manager (do not uninstall driver or software) before reboot to finish update.

    update will be made on vga driver and then all work fine gpu will be reconfigured again by windows

  • whodeytink

    Lost all my bookmarks from Chrome and Firefox. Had to reinstall printer driver, Had to reboot 8 times to get to a workable point. All add-ons gone from browsers. Downloads going to a different file location. I’m into hour 4 of trying to sort this crap out. @#$%ing Microsoft!!!!!!!!!!!!!

  • danielle_kaplan

    I’ve had a different problem. I tried installing Windows Update 1803 KB4103721 from both Windows Update and the Standalone Installer (326MB). In Windows Update it fails and offers to retry. With the standalone it aborts with the message “The update is not applicable to your computer.”

    Come on, Microsoft, get busy!

    • Aeonyx Areksu

      if you have windows 10 home N ,Try this, Start (windows logo) -> settings (left side of the pane) -> apps and features -> manage optional features -> check if you have windows media player there click and unninstal -> rebbot the computer -> try updating it again

      • danielle_kaplan

        Thanks for the suggestion, Aeonyx. Unfortunately, the problem is still there.

  • Christopher Stewart

    thanks Microsoft for the garbage update, looks like ill have to start everything from the task manager…

  • Massimiliano Bernini

    I discovered that if you installed a program from Iobit (like Driver Booster, for example) it creates a service called “LiveUpdate” with full name, as I remember, “LiveUpdateSvc”. Even if you remove the program the service will remain and this cause the KB4103721 update to fail to boot Windows after the update.
    Uninstall all Iobit programs and remove the service from the administrator command prompt typing “sc delete LiveUpdateSvc” (check it is the correct service name) and then you will be updating Windows without any problem.
    I experienced this issue on two computers and this has been the solution.

    • man quix

      thanks you helped me. i just connected my disk as external, located the iobit program and deleted the folder, installed back my disk to the laptop, and my laptop booted fine.

  • whodeytink

    THANKS! I just went through the process and was able to recover.

  • Bruce Dickinson

    KB4103721 didn’t fix the chrome for me, cmon microsoft what is going on man, actually i see no changes at all. sometimes though for like 60 seconds, everything, all windows becomes non-responsive then it works again.

  • brad sidrick

    I solved the problem by restarting from the login screen using the power icon in the bottom right corner. Cycling power did not work. The PC didn’t respond to function keys so restoring and entering a safe mode was not possible,

  • Peter Romano

    I have a Mushkin Reactor 1TB SATA3 SSD in my computer and after applying 1803 I was left with a black screen with a blue spinning circle. There was nothing I could do to get past this. The only thing I could do was after trying to boot the computer 3 times, was to go through the advanced troubleshooting and complete a system restore to the point prior to the update installation.
    So I am now running 1803 without the update KB 4103721 applied.

  • Ayman Saleh

    This worked for me after the black screen caused by this update:

    1. Restart and log in to safe mode (this will remove the update)
    2. Restart normally
    3. Initiate windows update, redownload and reinstall the update.
    4. Don’t restart your windows.
    5. Disable windows defender real time protection.
    6. Disable all startup programs and services except Microsoft services. (using msconfig).
    7. Now restart your Windows and the update will be installed smoothly.
    8. Reenable windows defender and other startup programs and services.