如果您无法在Windows 10中打开Windows Defender ，那么您今天来对地方了，我们将了解如何解决该问题。主要问题是Windows Defender会自动关闭，当您尝试启用它时，您根本无法启动WindowsDefender。当您单击“打开”选项时，您将收到一条错误消息“此应用已关闭且未监控您的计算机。”

如果您转到Settings > Update和Security > Windows DefenderDefender^{(Windows Defender)}中的实时保护已打开，但它是灰色的。此外，其他一切都已关闭，您无法对这些设置执行任何操作。有时主要问题是，如果您安装了第 3 方防病毒^(Antivirus)服务，Windows Defender会自动关闭。如果有多个安全服务在运行，它们旨在执行相同的任务，那么显然它们会产生冲突。因此，它始终建议只运行一个安全^(Security)应用程序，无论是Windows Defender还是第 3 方防病毒软件^(Antivirus)。

在某些情况下，问题是由于系统的日期和时间不正确引起的。如果是这种情况，您需要设置正确的日期和时间，然后再次尝试打开Windows Defender^{(ON Windows Defender)}。另一个重要问题是Windows 更新^{(Windows Update)}；如果Windows不是最新的，那么它很容易给Windows Defender带来麻烦。如果Windows未更新，则Windows 更新^{(Windows Update)}可能无法下载Windows Defender的^{(Windows Defender)}定义^(Definition)更新，这可能会导致该问题。这是执行 Windows Defender 定义更新^{(How to Perform Windows Defender Definition Update)}的方法.. 这是执行 Windows Defender 定义更新的方法^{(How to Perform Windows Defender Definition Update)}..

无论如何，现在您已经熟悉了导致Windows Defender出现问题的问题。因此，不要浪费任何时间，让我们看看如何在下面列出的故障排除指南的帮助下实际修复 Windows Defender 无法^{(Fix Windows Defender Does)}在Windows 10中启动。^{(Windows 10)}

修复 Windows Defender 无法启动

确保 创建一个还原点^{(create a restore point)} 以防万一出现问题。

方法 1：禁用 3rd 方防病毒服务^{(Method 1: Disable 3rd party Antivirus Services)}

1. 右键单击​​系统托盘中的防病毒程序图标^{( Antivirus Program icon)}并选择禁用。^(Disable.)

2. 接下来，选择防病毒软件将保持禁用的时间范围。^{( Antivirus will remain disabled.)}

注意：^(Note:)选择尽可能短的时间，例如 15 分钟或 30 分钟。

3. 完成后，再次尝试访问Windows Defender并检查您是否能够修复 Windows Defender 无法启动问题。^{(Fix Windows Defender Does Not Start Issue.)}

方法 2：设置正确的日期和时间^{(Method 2: Set Correct Date & Time)}

1. 点击任务栏上的日期和时间^{( date and time)}，然后选择“日期和时间设置^{(Date and time settings)}”。

2. 如果在 Windows 10 上，将“自动设置时间^{(Set Time Automatically)}”设置为“开启^(on)”。

3. 对于其他人，单击“Internet 时间”^{(“Internet Time”)}并勾选“自动与 Internet 时间服务器同步”。^{(“Automatically synchronize with an Internet time server.”)}

4. 选择服务器“ time.windows.com ”并点击更新和“确定”。^(“OK”.)您无需完成更新。点一下^(Just)，确定。

再次检查是否可以 修复 Windows Defender 无法启动问题^{( Fix Windows Defender Does Not Start issue)}，然后继续下一个方法。

方法 3： 启动 Windows Defender 服务^{(Method 3: Start Windows Defender Services)}

1. 按 Windows 键 + R 然后键入services.msc并按 Enter。

2. 在服务^(Services)窗口中找到以下服务：

Windows Defender 防病毒网络检查服务^{(Windows Defender Antivirus Network Inspection Service)}
Windows Defender 防病毒服务^{(Windows Defender Antivirus Service)}
Windows Defender 安全中心服务^{(Windows Defender Security Center Service)}

3. 双击它们并确保它们的启动^(Startup)类型设置为自动^{( Automatic)}，如果服务尚未运行，请单击启动。^(Start)

4. 单击应用，然后单击确定。^(OK.)

5. 重新启动您的 PC 以保存更改。

方法 4：从注册表编辑器启用 Windows Defender^{(Method 4: Enable Windows Defender from Registry Editor)}

1. 按 Windows 键 + R 然后键入regedit并按Enter打开注册表编辑器^{(Registry Editor)}。

2. 导航到以下注册表项：

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

3. 确保您在左侧窗格中突出显示了Windows Defender，然后在右侧窗格中双击DisableAntiSpyware DWORD。

注意：^(Note:)如果您没有找到Windows Defender密钥和DisableAntiSpyware DWORD，则需要手动创建它们。

4. 在DisableAntiSpyware DWORD的^{(DisableAntiSpyware DWORD)}数值^(Value)数据框中，将值从 1 更改为 0。

1：禁用 Windows Defender
0：启用 Windows Defender

5. 重新启动您的 PC 以保存更改并查看是否可以修复 Windows Defender 无法启动。^{(Fix Windows Defender Does Not Start.)}

方法 5：运行 SFC 和 DISM 工具^{(Method 5: Run SFC and DISM Tool)}

1.打开命令提示符^{(Command Prompt)}。用户可以通过搜索“cmd”然后按 Enter 来执行此步骤。

2.现在在cmd中输入以下内容并回车：

Sfc /scannow
sfc /scannow /offbootdir=c:\ /offwindir=c:\windows (If above fails then try this one)

3.等待^(Wait)上述过程完成，完成后，重新启动PC。

4.再次^(Again)打开 cmd 并输入以下命令并在每个命令后按回车键：

Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /ScanHealth
Dism /Online /Cleanup-Image /RestoreHealth

5. 让DISM命令运行并等待它完成。

6. 如果上述命令不起作用，请尝试以下操作：

Dism /Image:C:\offline /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows
Dism /Online /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows /LimitAccess

注意：^(Note:) 将^(Replace)C:RepairSourceWindows 替换为您的修复源（Windows 安装^{(Windows Installation)}或恢复光盘^{(Recovery Disc)}）。

7. 重新启动您的 PC 以保存更改并查看您是否能够修复 Windows Defender 无法启动。^{(Fix Windows Defender Does Not Start.)}

方法 6：运行 Windows 更新疑难解答^{(Method 6: Run Windows Update Troubleshooter)}

1. 打开控制面板^{(Control Panel)}，然后在右上角的搜索栏中搜索^{(Search Bar)}疑难解答，然后单击^{(Troubleshooting)}疑难解答^{(Troubleshooting)}。

2. 接下来，从左侧窗格中选择查看全部。^{(View all.)}

3. 然后从解决^{(Troubleshoot)}计算机问题列表中选择Windows 应用商店应用程序。^{(Windows Store Apps.)}

4. 按照屏幕上的说明运行Windows 更新疑难解答^{(Windows Update Troubleshoot)}。

5.重新启动您的PC，您可能能够修复Windows Defender无法启动。^{(Fix Windows Defender Does Not Start.)}

方法 7：取消选中代理^{(Method 7: Uncheck Proxy)}

1. 按 Windows 键 + R 然后输入inetcpl.cpl 并按回车键打开Internet 属性。^{(Internet Properties.)}

2. 接下来，转到连接选项卡^{(Connections tab)}并选择 LAN 设置。

3.取消选中为您的LAN使用^{(Uncheck Use)}代理服务器^{(Proxy Server)}并确保选中“自动检测设置^{(Automatically detect settings)}”。

4. 单击确定^(Ok)然后应用并重新启动您的 PC。

方法 8：尝试运行 Windows 更新^{(Method 8: Try to run Windows Update)}

1. 按 Windows 键 + I 打开设置^(Settings)，然后单击更新和安全。^{(Update & Security.)}

2. 从左侧菜单中选择Windows 更新。^{(Windows Update.)}

3. 现在在右侧窗格中的更新设置下单击^{(Update Settings)}高级选项。^{(Advanced options.)}

4.取消选中^(Uncheck)“当我更新 Windows 时为我提供其他 Microsoft 产品^{(“Give me updates for other Microsoft products when I update Windows.“)}的更新”选项。

5. 重新启动您的 Windows 并再次检查更新。

6. 您可能需要多次运行Windows Update才能成功完成更新过程。

7. 现在，一旦您收到“您的设备是最新^{(Your device is up to date)}的”消息，再次返回设置^(Settings)，然后单击高级^(Advanced)选项并选中“在我更新 Windows 时为其他Microsoft产品提供更新”。

8.再次^(Again)检查更新，您应该能够安装Windows Defender 更新^{(Windows Defender Update)}。

方法 9：手动更新 Windows Defender^{(Method 9: Manually Update Windows Defender)}

如果Windows Update无法下载Windows Defender的^{(Windows Defender)}定义^(Definition)更新，您需要手动更新 Windows Defender^{(manually update Windows Defender)}以修复 Windows Defender^{(Fix Windows Defender Does)}无法启动^(Start)。

方法 10：运行 CCleaner 和 Malwarebytes^{(Method 10: Run CCleaner and Malwarebytes)}

1. 下载并安装 CCleaner  & Malwarebytes。

2. 运行 Malwarebytes^{(Run Malwarebytes)(Run Malwarebytes)} 并让它扫描您的系统以查找有害文件。如果发现恶意软件，它将自动删除它们。

3. 现在运行 CCleaner 并选择 Custom Clean。

4. 在自定义清理下，选择 Windows 选项卡^{(Windows tab)}并勾选默认值，然后单击 分析^(Analyze)。

5. 分析完成后，确保您确定要删除要删除的文件。^{(Once Analyze is complete, make sure you’re certain to remove the files to be deleted.)}

6. 最后，点击 Run Cleaner 按钮，让CCleaner运行。

7. 要进一步清理您的系统，请 选择注册表选项卡^{(select the Registry tab)}，并确保选中以下内容：

8. 点击 Scan for Issues 按钮并允许CCleaner扫描，然后点击 Fix Selected Issues 按钮。

9. 当 CCleaner 询问“您要备份对注册表的更改吗？^{(Do you want backup changes to the registry?)}” 选择是^{( select Yes)}。

10. 备份完成后，单击 修复所有选定问题^{(Fix All Selected Issues)} 按钮。

11. 重新启动您的 PC 以保存更改。

方法 11：刷新或重置您的 PC^{(Method 11: Refresh or Reset your PC)}

1. 按Windows Key + I 打开设置^(Settings)，然后选择更新和安全。^{(Update & Security.)}

2. 从左侧菜单中选择恢复^(Recovery)，然后单击重置此 PC 下的“开始使用”。^{(Get started)}

3. 选择“保留我的文件^{(Keep my files)}”选项。

4. 按照屏幕上的说明完成该过程。

5. 这需要一些时间，您的计算机将重新启动。

方法 12：修复安装 Windows 10^{(Method 12: Repair Install Windows 10)}

这种方法是最后的手段，因为如果没有任何效果，这种方法肯定会修复您 PC 的所有问题。修复安装^{(Repair Install)}使用就地升级来修复系统问题，而不会删除系统上存在的用户数据。因此，请按照本文查看如何轻松修复安装 Windows 10。^{(How to Repair Install Windows 10 Easily.)}

为你推荐：^{(Recommended for you:)}

• 在 Windows 10 中禁用锁定屏幕^{(Disable the Lock Screen in Windows 10)}
• 修复 Window Defender 错误 0x800705b4^{(Fix Window Defender Error 0x800705b4)}
• 修复 Chrome 中的 ERR_INTERNET_DISCONNECTED^{(Fix ERR_INTERNET_DISCONNECTED in Chrome)}
• 以安全模式启动 PC 的 5 种方法^{(5 Ways to Start your PC in Safe Mode)}

就是这样，您已成功修复 Windows Defender 无法在 Windows 10 中启动，^{(Fix Windows Defender Does Not Start in Windows 10)}但如果您对本指南仍有任何疑问，请随时在评论部分提问。

Fix Windows Defender Does Not Start

If you аre unable to turn on Windows Defender in Windows 10 thеn you are at the right place today we will see how to fix the isѕue. The main issuе iѕ that Windows Defender is automaticallу turned off and when you try to enable it, you won’t be able to Start WindowsDefender at all. When you click on “Turn ON” optіоn, you will receive an error message “This app has been turned off and isn’t monitoring your computer.”

If you go to Settings > Update & Security > Windows Defender, you will see that the Real-time protection in Windows Defender is turned on, but it’s greyed out. Also, everything else is turned off, and you can’t do anything about these settings. Sometimes the main issue is that if you have installed a 3rd party Antivirus service, Windows Defender will automatically shut itself off. If there are more than one security services running which are designed to do the same task, then obviously they will create conflict. So, its always advised running only one Security application be it Windows Defender or the 3rd party Antivirus.

In some cases, the issue is caused because of the incorrect date and time of the system. If this is the case here, you need to set the correct date & time and then again try to turn ON Windows Defender. Another important issue is Windows Update; if Windows is not up to date, then it can easily cause trouble for Windows Defender. If Windows is not updated, then it’s possible that the Windows Update cannot download Definition update for Windows Defender, which is causing the issue. Here’s How to Perform Windows Defender Definition Update.. Here’s How to Perform Windows Defender Definition Update..

Anyway, now you are familiar with the issues which are causing the problem with Windows Defender. So without wasting any time let’s see how to actually Fix Windows Defender Does Not Start in Windows 10 with the help of below-listed troubleshooting guide.

Fix Windows Defender Does Not Start

Make sure to create a restore point just in case something goes wrong.

Method 1: Disable 3rd party Antivirus Services

1. Right-click on the Antivirus Program icon from the system tray and select Disable.

2. Next, select the time frame for which the Antivirus will remain disabled.

Note: Choose the smallest amount of time possible, for example, 15 minutes or 30 minutes.

3. Once is done, again try to access Windows Defender and check if you’re able to Fix Windows Defender Does Not Start Issue.

Method 2: Set Correct Date & Time

1. Click on the date and time on the taskbar and then select “Date and time settings.”

2. If on Windows 10, make “Set Time Automatically” to “on.”

3. For others, click on “Internet Time” and tick mark on “Automatically synchronize with an Internet time server.”

4. Select Server “time.windows.com” and click update and “OK”. You don’t need to complete the update. Just click, OK.

Again check if you can Fix Windows Defender Does Not Start issue or not then continue with the next method.

Method 3: Start Windows Defender Services

1. Press Windows Key + R then type services.msc and hit Enter.

2. Find the following services in the Services window:

Windows Defender Antivirus Network Inspection Service
Windows Defender Antivirus Service
Windows Defender Security Center Service

3. Double-click on each of them and make sure their Startup type is set to Automatic and click Start if the services are not already running.

4. Click Apply, followed by OK.

5. Reboot your PC to save changes.

Method 4: Enable Windows Defender from Registry Editor

1. Press Windows Key + R then type regedit and hit Enter to open Registry Editor.

2. Navigate to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

3. Make sure you have highlighted Windows Defender in the left window pane and then double click on DisableAntiSpyware DWORD in the right window pane.

Note: If you don’t find the Windows Defender key and DisableAntiSpyware DWORD, you need to manually create them.

4. In the Value data box of DisableAntiSpyware DWORD, change the value from 1 to 0.

1: Disable Windows Defender
0: Enable Windows Defender

5. Reboot your PC to save changes and see if you can Fix Windows Defender Does Not Start.

Method 5: Run SFC and DISM Tool

1. Open Command Prompt. The user can perform this step by searching for ‘cmd’ and then press Enter.

2. Now type the following in the cmd and hit enter:

Sfc /scannow
sfc /scannow /offbootdir=c:\ /offwindir=c:\windows (If above fails then try this one)

3. Wait for the above process to finish and once done, restart your PC.

4. Again open cmd and type the following command and hit enter after each one:

Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /ScanHealth
Dism /Online /Cleanup-Image /RestoreHealth

5. Let the DISM command run and wait for it to finish.

6. If the above command doesn’t work, then try on the below:

Dism /Image:C:\offline /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows
Dism /Online /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows /LimitAccess

Note: Replace the C:\RepairSource\Windows with your repair source (Windows Installation or Recovery Disc).

7. Reboot your PC to save changes and see if you’re able to Fix Windows Defender Does Not Start.

Method 6: Run Windows Update Troubleshooter

1. Open Control Panel and then search Troubleshooting in the Search Bar on the top right side and click on Troubleshooting.

2. Next, from the left window pane select View all.

3. Then from the Troubleshoot computer problems list select Windows Store Apps.

4. Follow on-screen instruction and let the Windows Update Troubleshoot run.

5. Restart your PC, and you may be able to Fix Windows Defender Does Not Start.

Method 7: Uncheck Proxy

1. Press Windows Key + R then type inetcpl.cpl and hit enter to open Internet Properties.

2. Next, Go to Connections tab and select LAN settings.

3. Uncheck Use a Proxy Server for your LAN and make sure “Automatically detect settings” is checked.

4. Click Ok then Apply and reboot your PC.

Method 8: Try to run Windows Update

1. Press Windows Key + I to open Settings then click on Update & Security.

2. From the left-hand menu select Windows Update.

3. Now under Update Settings in the right window pane click on Advanced options.

4. Uncheck the option “Give me updates for other Microsoft products when I update Windows.“

5. Restart your Windows and again check for updates.

6. You may have to run Windows Update more than once to complete the update process successfully.

7. Now as soon as you get the message “Your device is up to date“, again go back to Settings then click Advanced options and checkmark “Give me updates for other Microsoft products when I update Windows.”

8. Again check for updates and you should be able to install Windows Defender Update.

Method 9: Manually Update Windows Defender

If Windows Update cannot download Definition update for Windows Defender, you need to manually update Windows Defender to Fix Windows Defender Does Not Start.

Method 10: Run CCleaner and Malwarebytes

1. Download and install CCleaner & Malwarebytes.

2. Run Malwarebytes and let it scan your system for harmful files. If malware is found it will automatically remove them.

3. Now run CCleaner and select Custom Clean.

4. Under Custom Clean, select the Windows tab and checkmark defaults and click Analyze.

5. Once Analyze is complete, make sure you’re certain to remove the files to be deleted.

6. Finally, click on the Run Cleaner button and let CCleaner run its course.

7. To further clean your system, select the Registry tab, and ensure the following are checked:

8. Click on the Scan for Issues button and allow CCleaner to scan, then click on the Fix Selected Issues button.

9. When CCleaner asks “Do you want backup changes to the registry?” select Yes.

10. Once your backup has completed, click on the Fix All Selected Issues button.

11. Restart your PC to save changes.

Method 11: Refresh or Reset your PC

1. Press Windows Key + I to open Settings then select Update & Security.

2. From the left-hand menu select Recovery and click on “Get started” under Reset this PC.

3. Select the option to Keep my files.

4. Follow the instructions on the screen to complete the process.

5. This will take some time, and your computer will restart.

Method 12: Repair Install Windows 10

This method is the last resort because if nothing works out then, this method will surely repair all problems with your PC. Repair Install uses an in-place upgrade to repair issues with the system without deleting user data present on the system. So follow this article to see How to Repair Install Windows 10 Easily.

Recommended for you:

• Disable the Lock Screen in Windows 10
• Fix Window Defender Error 0x800705b4
• Fix ERR_INTERNET_DISCONNECTED in Chrome
• 5 Ways to Start your PC in Safe Mode

That’s it you have successfully Fix Windows Defender Does Not Start in Windows 10 but if you still have any questions regarding this guide then feel free to ask them in the comment’s section.

Related posts

• Fix Ca没有打开Windows Defender

• Fix Window Defender Error 0x800705b4

• Fix Windows Defender Update使用error 0x80070643失败

• Fix Service无法启动Windows Defender Error 0x80070422

• Fix Unable至Activate Windows Defender Firewall

• 如何播放Fix Firefox（2021）

• 9 Ways到Fix Twitter Videos不玩

• 5 Ways至Fix Steam Thinks Game运行Issue

• Fix Unable打开Local Disk（c :)

• error 0x807800C5失败了Fix Windows Backup

• Fix Unable安装Network Adapter Error Code 28

• Fix BAD_SYSTEM_CONFIG_INFO Error

• Fix Computer无法识别iPhone

• 如何在Windows 10中Fix Corrupted Registry

• Windows 10中的Fix Task Host Window Prevents Shut Down

• Windows 10缺少Fix VCRUNTIME140.dll

• Fix Windows Computer重新启动而不警告

• Windows Fix Host Process Windows Services已停止工作

• Fix USB Keeps Disconnecting and Reconnecting

• 如何在Windows上打开Fix Avast