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Full Guide to Repairing Black Screen Error When Booting Windows

  • Contents:


    Brief Introduction to Black Screen Error


    When booting Windows 10, Windows 8, Windows 7, or other Windows OS, you may get a black screen with blinking cursor, which is the so called Black Screen of Death (BSOD for short).

    Tip: Blue Screen of Death is also short for BSOD. In order to differentiate this BSOD from that BSOD, we temporarily call Black Screen of Death BKSOD.


    Once black screen error appears, there is nothing or just some error message on the screen, and users are always unable to do any operation. Therefore, almost all users are eager to find effective solutions. However, to get solutions, we should know reasons for BKSOD at first since solutions often come from causes.

    Next, let’s see why a black screen error is generated after we boot Windows.

    Causes for Black Screen of Death


    Both hardware issues and logical faults can be the cause for BKSOD. When there is something wrong with the following hardware components, users might be blocked by the black screen error: power supply, hard disk, internal memory, graphic card, motherboard, CPU, data line which connects display, and so on. And logical failures such as incorrect Windows security update, virus attack or malware invasion (this may cause MBR or system files damaged), mistaken operations (set wrong partition active), low disk space in C drive, and software incompatibility may also generate BKSOD. If we know the exact cause for black screen, it will be easy to solve the problem.

    But disappointingly, most people have difficulties in finding the exact cause.

    Actually, if there is nothing shown on the black screen or it just shows No Signal, the BKSOD error is largely caused by hardware issues. In addition, sometimes you will be clearly told which hardware is running in error, so please pay attention to the black screen when there are messages showing. Under these kinds of situations, checking hardware is recommended. However, if no sign shows hardware is the culprit for black screen, you’d better take logical faults into consideration at first. Later, we will show users how to repair BKSOD.

    Backup C Drive Before Repairing Black Screen of Death Error


    No matter which method you choose to repair black screen of death error, we highly suggest backing up personal data saved in C drive.

    Since Windows is already unbootable, you’ll need to use MiniTool Partition Wizard Boot Disc to create such a backup.

    Please download MiniTool Partition Wizard Bootable CD at first, which is an iso file.


    Then burn the downloaded iso file to CD, DVD, or portable devices like USB flash drive and memory stick.

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    After the boot disc is created, please boot your computer from the boot disc.

    backup data saved in C drive

    Here, all partitions are shown. To backup data saved in C drive, please select the very drive and choose "Copy Partition" feature from the left side. However, since no drive letter is shown in this mode, users need to view capacity, status, and other features to find the correct drive.

    Then, choose an unallocated space to hold the copy of C drive, edit drive size, and apply changes by following instructions. For more details, refer to the help tutorial Copy Partition.

    Once a backup is created, you can start fixing the black screen of death error without worrying about losing personal data.

    How to Repair Black Screen of Death Error for Windows Computers


    Check Hardware If Black Screen of Death Is Caused by Hardware Issue


    Note: all checks should be done after power has been off; in addition, if you do not have a good understanding of the internal structure of the computer, checking hardware may make your computer under great risk.


    1. Turn off your computer and then take apart mainframe of PC or laptop.

    internal structure of PC mainframe

    2. If you clearly know where each hardware should be connected, you can unplug all detachable devices like graphic card and memory bank, then clean every slot, interface, and port, and finally reconnect them one by one. If you doesn’t have a good understanding, please do cleaning and reconnection one after another.
    3. Pull out the signal line which connects the graphic card and display, clean both ports, and reconnect the signal line.

    After these steps, you can power on the computer and try booting it. If this works, we can say the black screen error results from hardware issues. However, if this doesn’t function, users can consider logical failures.

    Note:
    • if you are a laptop user, please don’t take apart your computer to test hardware unless you are skillful enough to master it. If not, you may bring more serious damage. In addition, if your laptop is under warranty, taking apart it will make the warranty useless. Therefore, laptop users had better check logical failures at first.

    • If the computer clearly shows BKSOD is caused by hardware error and both built-in recovery function and manual reconnection failed to work, users may need to replace or repair the device since this is the only solution.

    Follow These Steps If Black Screen Results from Logical Failures


    We have said there are lots of logical failures that can cause BKSOD, such as virus attack, software/driver incompatibility, wrong system settings, and faulty security updates. Therefore, it’s difficult to find the exact cause and naturally it’s not easy to find the solution. Aiming at this situation, we will show users how to deal with this kind of issues.

    Step 1: Check Whether There is Error Message on the Black Screen
    When the Black Screen of Death is caused by logical failures, there is cursor and users are often receiving corresponding error message which shows the exact cause and sometimes gives solutions. Under this situation, we can solve the problem with ease. Next, let’s see 2 examples.

    Example 1:

    bootmgr is missing black screen error

    This BKSOD error message shows Windows failed to boot due to missing BOOTMGR (a boot file for Windows). In most situations, it is due to setting wrong partition active.

    Generally, the partition saving Windows boot files including the BOOTMGR should be set active so that BIOS can locate the partition to find the boot manager and then give boot control to it. However, if we set the wrong partition active mistakenly, BOOTMGR will be missing since it cannot be located. Under this situation, to mark the correct partition active could solve the problem.

    In addition, if you receive the error message "Operating system not found", you can also try this way to fix the issue.

    How to Mark System Partition Active

    Please download MiniTool Partition Wizard Bootable CD, and then burn it to CD, DVD, or USB flash drive to create a boot disc.


    Then, start computer from Partition Wizard Boot Disc.

    set partition active

    Next, select the partition which saves BOOTMGR and tap on "Set Active" feature from the left side. If there is partition labeled as system reserved, it is the one you need to select. If there is no such partition, choose C drive.

    At last, click "Apply" button to make the change performed.

    Tip: if you set the correct partition active but the BOOTMGR is missing error still appears, this file may have been damaged or deleted. At this time, the best solution is to repair boot files via Windows installation Disc, which will be introduced latter.


    Example 2:

    repair windows os

    From the error message we know Windows couldn’t boot because a system file is missing or corrupted, and we are told to repair the file by using Windows installation CD or DVD. Since the exact solution has been given, we can solve the problem with ease. However, if you do not know how to run Windows system repair function added in Windows installation disc, please do like this:
    Boot computer via the installation CD or DVD, then choose language and click "Next" to get the screenshot below:

    windows system files are damaged

    Here, choose "Repair your computer" and then make operations in accordance with prompts.

    Nevertheless, if there is no error message or you are unclear of what the message tells, do the next step.

    Step 2: Check Whether Computer Can Boot in Safe Mode.

    In the article Blue Screen Error during Windows 10 Upgrade we have said Only the basic files and drivers necessary to run Windows will be started if we boot computer in Safe Mode. That is to say this will help detect whether the error is caused by system update, driver update, or other recent changes:

    • Boot computer and press F8 to get the advanced boot options.

      how to boot from safe mode

    • Highlight "Safe Mode" and click on Enter key.

    Windows Won’t Boot in Safe Mode

    If Windows won’t boot under Safe Mode, the black screen error might be caused by MBR damage or system file damage. At this time, try rebuilding MBR and fixing system.

    Trick: there are cases showing BKSOD results from C drive low disk space. To fix this issue, please extend C drive by using MiniTool Partition Wizard Boot Disc.


    How to Rebuild MBR or Enlarge C Drive without Windows OS
    Firstly, please download MiniTool Partition Wizard Bootable CD, an ISO file, and then burn it to USB flash drive, CD, or DVD.


    After that, boot computer via the bootable disc.

    Tip: users need to set the removable device or CD/DVD-ROM as the default boot disk if they are using Legacy BIOS + MBR boot mode.


    After successful boot, the following main interface will appear:

    rebuild MBR

    To rebuild MBR, please select the system disk, choose "Rebuild MBR" feature, and click "Apply" button to apply this change.

    extend c drive

    To extend C drive, please select C drive, choose "Extend Partition" feature, take free space from other partitions to enlarge C, and finally click "Apply" button.

    Well, what if Windows starts successfully from Safe Mode? Please see the following solutions.

    Windows Starts Successfully under Safe Mode

    If Windows works under this mode, black screen of death is caused by other factors, and here we list the following ones after doing lots of researches:
    Cause 1: made incorrect system settings.
    Cause 2: installed faulty system updates or incompatible apps.
    Cause 3: installed incompatible or faulty driver.
    Cause 4: graphics card driver is out of date or wrong.
    Cause 5: virus or malware attacks the computer.

    To deal with black screen of death error caused by these factors, users can try doing the following attempts:

    Attempt 1: Boot the computer with the "Last Known Good Configuration" option.
    The definition of "Last known good configuration" on Microsoft: "It's a Windows startup option that uses the most recent system settings that worked correctly. Every time you turn your computer off and Windows shuts down successfully, important system settings are saved in the registry. If a problem occurs, you can restart your computer using those settings."

    That is to say starting computer via this option will restore computer to the last state when it can boot successfully.

    Steps to access this option:
    1. Start computer and press on F8 before Windows is loaded.

    last known good configuration

    2. Highlight the option "Last Known Good Configuration" by using arrows "↑" and "↓" on keyboard.

    After that, wait and see whether Windows can start successfully. If it boots as usual, the BKSOD error has been fixed. If not, think about what operations you did prior to this error, and then undo the operation in Safe Mode. However, if you can’t remember, you may need to perform more operations.

    Attempt 2: Update Display Card Driver
    Without correct graphic card driver, the display won’t work properly, so users can try updating the driver to the latest version:
    1. Start computer and click F8 to get the Advanced Boot Options screen.

    safe mode with networking

    2. Highlight Safe Mode with Networking since the update needs network.

    3. After the computer boots successfully, please right click "Computer" icon on the desktop, choose "Properties", select "Device Manager", locate and double click the "Display Adapter" to show the device, right click the device, choose "Update Driver Software…", and finally do operations by following instructions. Of course, you can also download the newest graphic card driver from your manufacturer’s website for the update.

    Attempt 3: Uninstall Newly Installed Windows Updates
    It is reported that installing some Windows security updates like Update KB2607712 may generate black screen issues though Microsoft is unwilling to admit it. To uninstall such updates, please boot computer from Safe Mode, then type programs and features in Windows Search box, next open this app, choose View installed updates, and then locate updates under Windows category. If there are updates with the code name like KB2607712, KB976098 or KB915597, uninstall them. At last, restart computer from normal mode. Nevertheless, if this solution is proved to be useless, please perform the following operation.

    Attempt 4: Uninstall Newly Installed Programs
    Boot computer from Safe Mode, and then uninstall newly installed applications or programs.

    Attempt 5: Scan and remove Malware
    Some viruses are culprits for black screen error. If you haven’t installed antivirus software on your computer or the installed program isn’t powerful enough to block the viruses, the computer may have been infected by virus. Please boot computer from Safe Mode with Networking, then launch the installed antivirus software or download such a program from the internet, and do virus cleaning for the entire computer. This solution may work if all other solutions are proved to be ineffective.

    These are all our solutions, and now you can try one or some of them to repair your black screen of death error. Of course, they are just a part of solutions, and some of them may be useless for your situation. Therefore, we will continuously perfect the post once a new solution is found, and solutions from any people are also welcomed.