Windows Defender is a feature which you likely want to remove, and you can do this with PowerShell:

Write-Host "Uninstalling Windows Defender if any..."
$OSVersion = (([environment]::OSVersion.Version).Major)
$DefenderStatus = ((Get-WindowsFeature -Name "Windows-Defender-Features").Installed)

if (($OSVersion -eq '10') -and ($DefenderStatus -eq 'True')) {
    Dism.exe /online /Disable-Feature /FeatureName:Windows-Defender /Remove /NoRestart /quiet
}