Many people complain that Windows 10 forces them to use Windows Defender and that there is no way to disable it. Once you disable it using the Settings, the operating system re-enables it soon. Here is a solution which will allow you to disable Windows Defender in Windows 10 completely.
Windows Defender is the default antivirus app shipped with Windows 10. Earlier versions of Windows like Windows 8.1, Windows 8, Windows 7 and Vista also had it but it was less efficient previously as it only scanned spyware and adware. In Windows 8 and Windows 10, Defender is based on the Microsoft Security Essentials app which offers better protection by adding full blown protection against all kinds of malware. However, despite Microsoft's claims that it offers full protection, studies have found that third party antivirus apps still offer better protection. If you prefer to use a third party anti malware app, you might want to disable Windows Defender. Here is how you can disable it.
Windows Defender is an antivirus software which provides 'baseline protection' according to Microsoft and ships with Windows 8 and Windows 8.1. Since Windows 8, Windows Defender is the same application as Microsoft Security Essentials, which exists as a separate download for Windows 7, Vista and XP.
While Windows Defender provides very baseline protection, it slows down your PC considerably. I have done benchmarks with it enabled and then disabled and concluded that the filter driver it installs on the system slows down disk I/O noticeably. Every time, I download some small file from the Internet, it also makes my browser hang. If you are not happy with Windows Defender and would like to turn it off, follow this simple tutorial.