What should I do if Win10's built-in anti-virus software does not start?

Many people have encountered this situation, it can be said that a Win B preview version of a bug, after installing third-party security software, if you want to start the built-in security software Windows Defender will have problems, this problem is mainly the previous security After the software is uninstalled, some services are not enabled, and which service needs to be queried.
First, use the “Windows logo key + R & rdquo; open the run window, type "lds; services.msc"; or use the “tasklist /svc” command in the command prompt window, you can query the Windows Defender service The actual corresponding application can be enabled after finding the service.

Second, if it still can't be enabled, then it is really a BUG problem, we can right click on the "Start button" and select the "Command prompt (admin)" ;, enter “sc start WinDefend Enable” (without the quotation marks on both sides), and then press “ enter key & rdquo;, generally there will be no problem.