Powershell

powershell
$extensionId = "kghbmcgihmefcbjlfiafjcigdcbmecbf"

Write-Information "ExtensionID = $extensionID"
$extensionId = "$extensionId;https://clients2.google.com/service/update2/crx"
$regKey = "HKLM:\SOFTWARE\Policies\Google\Chrome\ExtensionInstallForcelist"
if (!(Test-Path $regKey)) {
    New-Item $regKey -Force
    Write-Information "Created Reg Key $regKey"
}

# Add Extension to Chrome
$extensionsList = New-Object System.Collections.ArrayList
$number = 0
$noMore = 0
do{
    $number++
    Write-Information "Pass : $number"
    try {
        $install = Get-ItemProperty $regKey -name $number -ErrorAction Stop
        $extensionObj = [PSCustomObject]@{
            Name = $number
            Value = $install.$number
        }
        $extensionsList.add($extensionObj) | Out-Null
        Write-Information "Extension List Item : $($extensionObj.name) / $($extensionObj.value)"
    } catch {
        $noMore = 1
    }
} until($noMore -eq 1)

$extensionCheck = $extensionsList | Where-Object {$_.Value -eq $extensionId}
if($extensionCheck) {
    $result = "Extension Already Exists"
    Write-Information "Extension Already Exists"
} else {
    $newExtensionId = $extensionsList[-1].name + 1
    New-ItemProperty HKLM:\SOFTWARE\Policies\Google\Chrome\ExtensionInstallForcelist -PropertyType String -Name $newExtensionId -Value $extensionId | Out-Null
    $result = "Installed"
}

powershell
$extensionId = "cajjbdjepfpnnbnhnilgeikaaicpnbhn"

$settings = 
[PSCustomObject]@{
    Path  = "SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallForcelist"
    Value = "$extensionId"
    Name  = ++$count
} | group Path

foreach($setting in $settings){
    $registry = [Microsoft.Win32.Registry]::LocalMachine.OpenSubKey($setting.Name, $true)
    if ($null -eq $registry) {
        $registry = [Microsoft.Win32.Registry]::LocalMachine.CreateSubKey($setting.Name, $true)
    }
    $setting.Group | %{
        $registry.SetValue($_.name, $_.value)
    }
    $registry.Dispose()
}

powershell
$xpiUrl = "https://addons.mozilla.org/firefox/downloads/file/4262658/heylogin-1.1.0.6517.xpi"

$settings =
[PSCustomObject]@{
    Path  = "SOFTWARE\Policies\Mozilla\Firefox\Extensions\Install"
    Value = "$xpiUrl"
    Name  = ++$count
}| group Path

foreach($setting in $settings){
    $registry = [Microsoft.Win32.Registry]::LocalMachine.OpenSubKey($setting.Name, $true)
    if ($null -eq $registry) {
        $registry = [Microsoft.Win32.Registry]::LocalMachine.CreateSubKey($setting.Name, $true)
    }
    $setting.Group | %{
        $registry.SetValue($_.name, $_.value)
    }
    $registry.Dispose()
}