Quick solution for Windows Defender that can't be started in Win10

Some users have found that the built-in Windows Defender does not start properly after upgrading Win10. I found that these users are basically upgraded from Win7, and may have used MSE before. Although the MSE will be cleared after the upgrade under normal circumstances, there are also cases where the cleanup is not clean, which may cause Windows Defender startup problems. There are two steps to solve this problem.

First, clear the MSE residue

1, locate the following path in the file explorer:

C:\\Program Files\\Microsoft Security Client\\< Br>

2, right click on the Setup.exe file, select Properties → Compatibility & Rarr; Change settings for all users

3, check “Run in compatibility mode”, drop down menu Select Windows7, click “OK Save

4. Run the command prompt as an administrator and execute the following command:

C:\\Program Files\\Microsoft Security Client\\setup .exe /x /disableoslimit

5. After the command is executed, select “Uninstall", restart the computer

Second, restore the Windows Defender service

1, Cortana search bar input "Services", press Enter to enter (can also run services.msc on the run)

2, check whether Windows Defender related services are disabled, if disabled, try to enable, as follows Figure ——

3. You can also run the command prompt in administrator mode and execute the following command to start the service:

sc config WinDefen d start= auto

sc start WinDefend

It should be noted that if a third-party killing software is installed on the computer, Windows Defender will not start by default.

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