It will be a good idea to using them both in same time .
Windows Defender (which now it's call Microsoft Defender ) ,
In many recent tests, achieved very good results,
It has good protection capabilities and very low false positives.
In the past, the built-in antivirus software was often considered useless.
But obviously, Microsoft does try to improve it,
And MD's current performance is no longer lost to traditional antivirus software.
I think MB provide better PUP/PUA、Trojan、adware detection rate ,
and the premium version of MB had more useful protect , such as ransomware and zero-days protect, etc.
My laptop is using MD + MB Permium,
sometimes , MB warns for me but MD doesn't ,
such as malicious websites, scam/phishing websites , MB did better then MD this part ,
there are also several experiences that MB blocked adware for me.
Several times on the Internet, some well-known websites were hacked, the mining script is implanted,
and MD is weak in this regard , most of them are detected and blocked by MB first.
If the cost is acceptable to you, I think you can take a try ,
but before purchase , try the MB's 14 days free trial first ,
and see you like or not .
