如果您的Windows PC 拒绝打开(Windows PC refuses to turn on)并显示“缺少Bootmgr ”错误，有很多方法可以解决此问题并正常启动 PC。
此错误有多种原因，但通常发生在 PC 上的系统文件损坏问题时。
1.重启你的电脑(Restart Your PC)
当您第一次遇到“缺少 Bootmgr”错误并且操作系统尚未启动（您无法进入桌面）时，请重新启动您的 PC。
- 使用 PC 上的电源(Power)按钮将其关闭（您可能需要按住它长达 30 秒），然后按相同的按钮重新打开 PC。
- 或者，按Ctrl + Alt + Del重新启动 PC。
- 这会重置几个系统项目，如果您的问题是由小故障引起的，这应该可以解决它。
2. 检查可启动媒体
继续并弹出任何可能会混淆您的计算机的USB驱动器、CD、DVD(DVDs)、蓝光光盘等，让计算机认为它是可启动设备，而实际上它不是。(Blu-ray)默认情况下，大多数计算机都设置为从CD/DVD驱动器和USB驱动器启动，然后再从主硬盘驱动器启动。如果您有多个硬盘驱动器，请阅读下面的下一个解决方案。
3.更改BIOS中的引导顺序(Change the Boot Order in BIOS)
如果 PC 不是从主硬盘驱动器启动，而是从没有启动计算机所需文件的附加驱动器启动，也会出现“缺少 Bootmgr”错误。要解决此问题，请更改计算机BIOS中的引导顺序，并按照以下步骤将主驱动器设置为引导顺序中的第一个：
- 关掉你的电脑。
- 引导您的 PC 进入 BIOS 模式(Boot your PC into BIOS mode)。在大多数 PC 中，您可以按住F2键，然后按电源(Power)按钮来执行此操作。如果此按钮组合不适合您，请查看您的 PC 制造商的网站。
- 在 BIOS 中，使用箭头键转到引导选项卡。(Boot)
- 使用箭头键突出显示Boot Option #1，然后按Enter。
- 选择安装Windows的硬盘驱动器，然后按Enter。
- 按右箭头键访问安全(Security)选项卡并选择安全启动(Secure Boot)。
- 突出显示Secure Boot Control，按Enter，然后选择Disabled。
- 按右箭头键转到“保存并退出”(Save & Exit)选项卡。
- 选择保存更改并退出(Save Changes and Exit)。
希望(Hopefully)这将修复错误。如果没有，请继续执行下面列出的步骤。
4.从您的 PC 上拔下 USB 和其他设备(Unplug USB and Other Devices From Your PC)
如果您已将任何USB或其他设备连接到您的计算机，请将它们从您的 PC 上拔下，看看是否能解决问题。
有时，不兼容的外部设备可能会导致Windows出现问题。
5.运行启动修复(Run Startup Repair)
Windows有一个启动修复工具来解决与您的 PC 启动相关的 (lated to the boot of your PC. )问题。(issues re)
使用Windows 10或 Windows 7 安装驱动器（光盘或USB驱动器）并按照以下步骤启动和使用启动修复。您可以阅读我们的指南，了解如何使用 Windows 创建可启动 USB 驱动器(create a bootable USB drive with Windows)。
- 将(Insert)Windows安装光盘/驱动器插入计算机。
- (Boot)从此安装驱动器启动您的 PC。如上面BIOS(BIOS)部分所示更改引导顺序(Change the boot order)，并将安装驱动器设置为主引导驱动器。
- 从下拉菜单中选择语言和货币等选项，然后选择下一步(Next)。
- 选择修复您的计算机(Repair your computer)。
- 选择疑难解答(Troubleshoot)，然后选择启动修复(Startup Repair)。
- 选择您的 Windows 安装。
- Windows 应该开始修复您的计算机。
6.重建引导配置数据(Rebuild the Boot Configuration Data)
当引导配置数据出现问题时，也会显示“ Bootmgr is missing”错误。幸运的是，可以使用一些命令和Windows安装驱动器重建这些数据。
- (Boot)从可启动的Windows(Windows)安装驱动器启动您的 PC 。
- 在第一个屏幕上选择所需的详细信息，然后选择Next。
- 选择修复您的计算机(Repair your computer)。
- 选择疑难解答(Troubleshoot)，然后选择命令提示符(Command Prompt)。
- 在命令提示符中，键入bootrec /RebuildBcd并按Enter。
- 如果该命令找到Windows安装，它会要求您向其中添加一个条目。键入Yes并按Enter。
- 如果该命令找不到Windows安装，请一一键入以下命令以重建BCD。如果 C 不是您的 Windows 安装驱动器，请更改(Change)C的位置。
Bcdedit /export C:\BCD_Backup
ren C:\boot\bcd bcd.old
Bootrec /rebuildbcd
- 执行命令后，重新启动 PC。
- 再次选择修复选项，Windows将开始修复您的 PC。
7.使用系统还原(Use System Restore)
系统还原(System Restore)可帮助您的 PC 恢复工作状态。值得恢复系统还原点之一，以查看“Bootmgr is missing”错误是否得到修复。
- (Boot)从Windows安装驱动器(Windows)启动您的 PC，然后选择修复您的计算机(Repair your computer)。
- 选择疑难解答(Troubleshoot)，然后选择系统还原(System Restore)。
- 选择您的Windows安装并在系统还原(System Restore)向导的第一个屏幕上选择下一步。(Next)
- 在列表中选择最近的还原点，然后选择底部的下一步。(Next)
- 选择完成(Finish)以开始恢复您的 PC。
PC 恢复后应该可以正常工作，但如果不能，请尝试下面列出的其他修复程序。
8.全新安装 Windows 10 或 7(Clean Install Windows 10 or 7)
如果您的 PC 尽管按照上述方法仍然显示“缺少 Bootmgr”，则最好在您的 PC 上全新安装 Windows 10(clean install Windows 10)或 Windows 7。
当您全新安装Windows时，存储在您计算机上的所有内容都将被删除并安装新版本的操作系统。这有助于解决由现有损坏或丢失的系统文件引起的任何问题。
查看我们的指南，了解如何(how to clean install Windows)在您的计算机上全新安装 Windows。
9.更换你的硬盘(Replace Your Hard Drive)
如果上述步骤均未修复“缺少 Bootmgr”错误，则您的硬盘本身可能是问题所在，在这种情况下应更换它。您可以在许多网站（即Crucial.com ）上轻松地在线找到兼容的硬盘驱动器。
如果您有幸在错误开始发生之前备份您的系统，您可以阅读我们的指南，了解如何将 Windows 10 备份恢复(restore a Windows 10 backup )到新驱动器。
请在下面发表评论，告诉我们上面提到的哪种方法修复了您 PC 上的“Bootmgr is missing”错误。
How to Fix Bootmgr is Missing in Windows 10
If your Windows PC refuses to turn on and displays the “Bootmgr is missing” error, there are many ways to fix this issue and boot up the PC normally.
There are various reasons for this error but it generally occurs when there’s an issue with corruption of system files on the PC.
1. Restart Your PC
When you first encounter the “Bootmgr is missing” error and the operating system hasn’t launched (you can’t get to the desktop), restart your PC.
- Use the Power button on your PC to turn it off (you may need to hold it down for up to 30 seconds), and then press the same button to turn the PC back on.
- Alternatively, press Ctrl + Alt + Del to restart your PC.
- This resets several system items, and if your issue is caused by a minor glitch, this should fix it.
2. Check for Bootable Media
Go ahead and eject any USB drives, CDs, DVDs, Blu-ray discs, etc. that could possibly be confusing your computer by making it think it’s a bootable device when it’s really not. By default, most computers are setup to boot from a CD/DVD drive and a USB drive before booting from the primary hard drive. If you have multiple hard drives, read the next solution below.
3. Change the Boot Order in BIOS
The “Bootmgr is missing” error can also occur if the PC is not booting from the primary hard drive but instead from an additional drive that doesn’t have the required files to boot the computer. To fix this, change the boot order in your computer’s BIOS and set your primary drive as first in the boot order by following the steps below:
- Turn your PC off.
- Boot your PC into BIOS mode. In most PCs, you can press and hold the F2 key and then press the Power button to do so . Check your PC manufacturer’s website if this button combination doesn’t work for you.
- In BIOS, head to the Boot tab using the arrow keys.
- Use the arrow keys to highlight Boot Option #1 and press Enter.
- Select your hard drive where Windows is installed and press Enter.
- Press the right-arrow key to access the Security tab and select Secure Boot.
- Highlight Secure Boot Control, press Enter, and select Disabled.
- Press the right-arrow key to go to the Save & Exit tab.
- Select Save Changes and Exit.
Hopefully this will fix the error. If not, proceed to the steps listed below.
4. Unplug USB and Other Devices From Your PC
If you’ve connected any USB or other devices to your computer, unplug them from your PC and see if that fixes the issue.
Sometimes, an incompatible external device can cause issues with Windows.
5. Run Startup Repair
Windows has a startup repair tool to address issues related to the boot of your PC.
Use a Windows 10 or Windows 7 installation drive (either disc or a USB drive) and follow the steps below to launch and use startup repair. You can read our guide on how to create a bootable USB drive with Windows.
- Insert a Windows installation disc/drive into your computer.
- Boot your PC from this installation drive. Change the boot order as shown in the BIOS section above and set your installation drive as the primary boot drive.
- Select options like language and currency from the dropdown menus, and select Next.
- Choose Repair your computer.
- Select Troubleshoot and then select Startup Repair.
- Select your Windows installation.
- Windows should start fixing your computer.
6. Rebuild the Boot Configuration Data
A “Bootmgr is missing” error is also displayed when there’s an issue with the boot configuration data. Luckily, this data can be rebuilt using a few commands and a Windows installation drive.
- Boot your PC from a bootable Windows installation drive.
- Select the required details on the first screen, and select Next.
- Choose Repair your computer.
- Select Troubleshoot and then select Command Prompt.
- In Command Prompt, type bootrec /RebuildBcd and press Enter.
- If the command finds a Windows installation, it asks you to add an entry to it. Type Yes and press Enter.
- If the command can’t find a Windows installation, type the following commands one-by-one to rebuild BCD. Change where it says C if C is not your Windows installation drive.
Bcdedit /export C:\BCD_Backup
ren C:\boot\bcd bcd.old
Bootrec /rebuildbcd
- When the command has executed, restart your PC.
- Choose the repair option again and Windows will start fixing your PC.
7. Use System Restore
System Restore helps bring your PC back to a working condition. It’s worth restoring one of the system restore points to see if the “Bootmgr is missing” error gets fixed.
- Boot your PC from a Windows installation drive and select Repair your computer.
- Select Troubleshoot and then choose System Restore.
- Select your Windows installation and select Next on the first screen of the System Restore wizard.
- Choose the most recent restore point in the list and select Next at the bottom.
- Select Finish to start restoring your PC.
The PC should work properly once it’s restored but if not, try the other fixes listed below.
8. Clean Install Windows 10 or 7
If your PC continues to display “Bootmgr is missing” despite following the above methods, it may be a good idea to clean install Windows 10 or Windows 7 on your PC.
When you clean install Windows, everything stored on your computer is removed and a fresh version of the operating system is installed. This helps fix any issues caused by existing corrupted or missing system files.
Take a look at our guide to learn how to clean install Windows on your computer.
9. Replace Your Hard Drive
If none of the steps mentioned above fixed the “Bootmgr is missing” error, your hard drive itself could potentially be the issue, in which case it should be replaced. You can easily find a compatible hard drive online on many sites, namely Crucial.com.
If you were lucky enough to backup your system before the error starting occurring, you can read our guide on how to restore a Windows 10 backup to your new drive.
Do leave a comment below to tell us which method mentioned above fixed the “Bootmgr is missing” error on your PC.
