win10 windows defender无法开启病毒和威胁防护，怎么办？

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender]
"DisableAntiSpyware"=dword:00000000
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection]
"DisableBehaviorMonitoring"=dword:00000000
"DisableIOAVProtection"=dword:00000000
"DisableOnAccessProtection"=dword:00000000
"DisableRealtimeMonitoring"=dword:00000000
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SecurityHealthService]
"Start"=dword:00000002
网上（包括win官网论坛）回复均无法解决问题，请君复制以上内容到文本，改扩展名为.reg，运行即可，大恩不言谢！