修复 Window Defender 错误 0x800705b4：  ^{(Fix Window Defender Error 0x800705b4: )}Windows Defender是^{(Windows Defender)}Windows 10中的内置安全工具，可防止恶意软件和间谍软件。Windows Defender的工作是使您的系统免受外部威胁，并作为防病毒^(Antivirus)程序积极工作。出于这个原因，许多用户不使用 3rd 方防病毒^(Antivirus)应用程序，他们只依赖Windows Defender，只要Windows Defender完成它的工作，这似乎很好。最好的一点是您无需付费，因为它是Microsoft的免费软件工具，并且预装了Windows。

现在，当您由于错误代码 0x800705b4 或 0x80508020 而无法启动Windows Defender时会发生什么。^{(Windows Defender)}好吧，如果Windows Defender无法启动，那么您的系统将容易受到恶意软件和病毒的攻击，如果您问我，这不是一件好事。尝试运行Windows Defender时，您将收到以下错误消息：

The service couldn’t be started.
This operation returned because the timeout period expired.
Error code: 0x800705b4

或者

Windows Defender couldn’t turn on real-time protection.
This operation returned because the timeout period expired.
Error code: 0x800705b4

出现意外问题。安装^(Install)任何可用的更新，然后尝试再次启动该程序。有关安装更新的信息，请参阅帮助^(Help)和支持^(Support)。
错误代码：0x80508020。

用户报告说他们首先收到错误代码 0x80508020，当他们尝试单击关闭^(Close)时，他们收到另一个错误代码，即 0x800705b4。因此，我们需要解决这两个错误消息才能成功启动Windows Defender。Windows Defender 错误 0x800705b4^{(Windows Defender Error 0x800705b4)}或 0x80508020的主要原因似乎是另一个似乎与之冲突的第三方防病毒服务。^(Antivirus)程序发生冲突是很自然的，因为它们都执行相同的功能，因此您只需要系统上的一个活动程序。

因此，您需要禁用 3rd 方防病毒^(Antivirus)服务才能成功启动Windows Defender并修复与它相关的上述错误代码。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 Window Defender 错误 0x800705b4^{(Fix Window Defender Error 0x800705b4)}或 0x80508020。

修复 Window Defender 错误 0x800705b4^{(Fix Window Defender Error 0x800705b4)}或 0x80508020

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)}，然后选择禁用。^(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：选择尽可能少的时间，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 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

方法 2：启用 Windows 防火墙^{(Method 2: Enable Windows Firewall)}

1.按 Windows 键 + I 然后选择控制面板。^{( Control Panel.)}

2.下一步，点击系统和安全， ^{( System and Security and )}然后点击Windows防火墙。^{(Windows Firewall.)}

3.现在从左侧窗格中单击打开或关闭 Windows 防火墙。^{(Turn Windows Firewall on or off.)}

4.选择打开 Windows 防火墙并重新启动您的 PC。^{(Select Turn ON Windows Firewall and restart your PC. )}再次尝试打开Windows Defender并查看是否能够 修复 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

如果上述方法不起作用，请确保按照完全相同的步骤再次打开防火墙。

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。

5.重新启动您的 PC 以保存更改。

方法 4：注册表修复^{(Method 4: Registry Fix)}

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.确保您已在左侧窗格中突出显示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，那么您需要手动创建它们。

4.在DisableAntiSpyware DWORD^{(DisableAntiSpyware DWORD)}的数值数据框中，将数值从 1 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，看看您是否能够 修复 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

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

1.按Windows Key + X然后单击命令提示符（管理员）。^{( Command Prompt(Admin).)}

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.等待上述过程完成，完成后重新启动您的电脑。

4.再次打开cmd并输入以下命令并在每个命令后按回车键：

a) Dism /Online /Cleanup-Image /CheckHealth
b) Dism /Online /Cleanup-Image /ScanHealth
c) 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 替换为修复源的位置（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 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

方法 6：运行 CCleaner 和 Malwarebytes^{(Method 6: 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。

3.如果发现恶意软件，它将自动删除它们。

4.现在运行 CCleaner  ，在“Cleaner”部分的“ Windows ”选项卡下，我们建议检查以下要清理的选项：

5.一旦您确定检查了正确的点，只需单击 Run Cleaner， 然后让 CCleaner 运行。

6.要清理您的系统，请进一步选择注册表^(Registry)选项卡并确保选中以下内容：

7.选择Scan for Issue并允许CCleaner扫描，然后单击 Fix Selected Issues。

8.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。

9.备份完成后，选择Fix All Selected Issues。

10.重新启动您的 PC 以保存更改。

方法 7：运行 Windows 更新疑难解答^{(Method 7: Run Windows Update Troubleshooter)}

1.现在在Windows 搜索^{(Windows Search)}栏中键入“疑难解答”，然后单击疑难解答。^{(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.重新启动您的电脑，您可能能够 修复 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

方法 8：工作解决方案^{(Method 8: Working Solution)}

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^{(Update Settings)}下单击高级选项。^{(Advanced options.)}

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

5.重新启动 Windows 并再次检查更新。

6.您可能需要多次运行Windows 更新^{(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 更新^{(Windows Update)}无法下载Windows Defender的^{(Windows Defender)}定义^(Definition)更新，则您需要手动更新 Windows Defender^{(manually update Windows Defender)}以修复 Window Defender 错误 0x800705b4^{(Fix Window Defender Error 0x800705b4)}。

方法 10：执行干净启动^{(Method 10: Perform Clean boot)}

然后尝试更新 Windows Defender 定义^{(Update Windows Defender Definition)}和 Windows

1.按Windows Key + R按钮，然后键入“msconfig”并单击“确定”。

2.在常规选项卡下，确保选中“选择性启动” 。^{( ‘Selective startup’)}

3.取消选中选择性启动下的“加载启动项”。^{(‘Load startup items)}

4.选择服务^(Service)选项卡并选中“隐藏所有 Microsoft 服务”框。^{( ‘Hide all Microsoft services.’)}

5.现在单击“全部禁用”^{( ‘Disable all’)}以禁用所有可能导致冲突的不必要服务。

6.在启动选项卡上，单击“打开任务管理器”。^{(‘Open Task Manager.’)}

7.现在在启动选项卡^{( Startup tab)}（在任务管理器内）禁用所有^{( disable all )}启用的启动项。

8.单击确定，然后重新启动。^{(Restart. )}再次尝试访问Windows Defender，您也许可以。

9.再次按下Windows key + R按钮并输入“msconfig”并单击“确定”。

10.在常规选项卡上，选择正常启动选项^{( Normal Startup option)}，然后单击确定。

11.当提示您重新启动计算机时，单击重新启动。^{( click Restart. )}这肯定会帮助您修复 Window Defender 错误 0x800705b4。^{(Fix Window Defender Error 0x800705b4.)}

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Recovery，然后单击Reset this PC 下的“ Get started ”。

3.选择 保留我的文件^{(Keep my files)}的选项。

4.按照屏幕上的说明完成该过程。

5.这将需要一些时间，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，那么这种方法肯定会修复您 PC 的所有问题。修复安装^{(Repair Install)}仅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 嗯，我们在 Microsoft Edge 中无法访问此页面错误^{(Fix Hmm, we can’t reach this page error in Microsoft Edge)}
• 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 Window Defender 错误 0x800705b4^{(Fix Window Defender Error 0x800705b4)}，但如果您对本指南仍有任何疑问，请随时在评论部分提出。

Fix Window Defender Error 0x800705b4

Fix Window Defender Error 0x800705b4: Windows Defender is a built-in security tool inside Windows 10 which protects against malware & spyware. Windows Defender does its job to make your system secure from external threats and actively work as an Antivirus program. For this reason, many users don’t use 3rd party Antivirus application and they solely rely on Windows Defender, which seems fine as long as Windows Defender does its job. The best thing about it is that you don’t need to pay for it as it’s freeware tool from Microsoft and it comes pre-installed with Windows.

Now, what happens when you can’t start Windows Defender because of error code 0x800705b4 or 0x80508020. Well, if Windows Defender can’t start then your system will become vulnerable to malware & viruses, which is not a good thing if you ask me. You will receive the following error message while trying to run Windows Defender:

The service couldn’t be started.
This operation returned because the timeout period expired.
Error code: 0x800705b4

OR

Windows Defender couldn’t turn on real-time protection.
This operation returned because the timeout period expired.
Error code: 0x800705b4

An unexpected problem occurred. Install any available updates, and then try to start the program again. For information on installing updates, see Help and Support.
Error code: 0x80508020.

Users reported that they first receive the error code 0x80508020 and when they tried to click on Close they got another error code which is 0x800705b4. So we need to resolve both of these error messages in order to start Windows Defender successfully. The main reason of Windows Defender Error 0x800705b4 or 0x80508020 seems to another 3rd party Antivirus service which seems to be conflicting with it. It’s only natural for the programs to get into a conflict as both of them performs the same function, so you need only once an active program on your system.

So you need to disable the 3rd party Antivirus service in order to start Windows Defender successfully and fix the above error codes associated with it. So without wasting any time let’s see how to actually Fix Window Defender Error 0x800705b4 or 0x80508020 with the help of below-listed troubleshooting guide.

Fix Window Defender Error 0x800705b4 or 0x80508020

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 done, again try to access Windows Defender and check if you’re able to Fix Window Defender Error 0x800705b4.

Method 2: Enable Windows Firewall

1.Press Windows Key + I then select Control Panel.

2.Next, click on System and Security and then click on Windows Firewall.

3.Now from the left window pane click on Turn Windows Firewall on or off.

4.Select Turn ON Windows Firewall and restart your PC. Again try to open Windows Defender and see if you’re able to Fix Window Defender Error 0x800705b4.

If the above method doesn’t work make sure to follow the exact same steps to turn on your Firewall again.

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: Registry Fix

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 then you need to manually create both of 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 are able to Fix Window Defender Error 0x800705b4.

Method 5: Run SFC and DISM Tool

1.Press Windows Key + X then click on Command Prompt(Admin).

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:

a) Dism /Online /Cleanup-Image /CheckHealth
b) Dism /Online /Cleanup-Image /ScanHealth
c) 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 the location of your repair source (Windows Installation or Recovery Disc).

7.Reboot your PC to save changes and see if you’re able to Fix Window Defender Error 0x800705b4.

Method 6: Run CCleaner and Malwarebytes

1.Download and install CCleaner & Malwarebytes.

2.Run Malwarebytes and let it scan your system for harmful files.

3.If malware is found it will automatically remove them.

4.Now run CCleaner and in the “Cleaner” section, under the Windows tab, we suggest checking the following selections to be cleaned:

5.Once you’ve made certain the proper points are checked, simply click Run Cleaner, and let CCleaner run its course.

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

7.Select Scan for Issue and allow CCleaner to scan, then click Fix Selected Issues.

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

9.Once your backup has completed, select Fix All Selected Issues.

10.Restart your PC to save changes.

Method 7: Run Windows Update Troubleshooter

1.Now type “troubleshooting” in Windows Search bar 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 Window Defender Error 0x800705b4.

Method 8: Working Solution

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 in order 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 check mark “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 is not able to download Definition update for Windows Defender then you need to manually update Windows Defender in order to Fix Window Defender Error 0x800705b4.

Method 10: Perform Clean boot

then Try to Update Windows Defender Definition and Windows

1.Press the Windows Key + R button, then type ‘msconfig’ and click OK.

2.Under General tab under, make sure ‘Selective startup’ is checked.

3.Uncheck ‘Load startup items‘ under selective startup.

4.Select Service tab and check the box ‘Hide all Microsoft services.’

5.Now click ‘Disable all’to disable all the unnecessary services which might cause conflict.

6.On Startup tab, click ‘Open Task Manager.’

7.Now in Startup tab (Inside Task Manager) disable all the startup items which are enabled.

8.Click OK and then Restart. Again try to access Windows Defender and this you may be able to.

9.Again press the Windows key + R button and type ‘msconfig’ and click OK.

10.On the General tab, select the Normal Startup option, and then click OK.

11.When you are prompted to restart the computer, click Restart. This would definitely help you Fix Window Defender Error 0x800705b4.

Method 11: Refresh or Reset your PC

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

2.From 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 just 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 Hmm, we can’t reach this page error in Microsoft Edge
• Fix ERR_INTERNET_DISCONNECTED in Chrome
• 5 Ways to Start your PC in Safe Mode

That’s it you have successfully Fix Window Defender Error 0x800705b4 but if you still have any questions regarding this guide then feel free to ask them in the comment’s section.

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