Test Windows proxy

ProxyTest.ps1

#No Proxy
function NoProxy {
    Param($URL);
    $WC = New-Object Net.WebClient
    $WC.DownloadString($URL)
}

#Proxy 1
function Proxy1 {
    Param($URL);
    $ProxyAddr = (Get-ItemProperty 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings').ProxyServer
    $Proxy = New-Object System.Net.WebProxy
    $Proxy.Address = $ProxyAddr
    $Proxy.useDefaultCredentials = $true

    $WC = New-Object System.Net.WebClient
    $WC.proxy = $Proxy
    $WC.DownloadString($URL)
}

#Proxy 2
function Proxy2 {
    Param($URL);
    $Proxy = [System.Net.WebRequest]::GetSystemWebProxy()
    $Proxy.Credentials = [System.Net.CredentialCache]::DefaultCredentials

    $WC = New-Object System.Net.WebClient
    $WC.Proxy = $Proxy
    $WC.DownloadString($URL)
}

#Proxy 3
function Proxy3 {
    Param($URL);
    $WC = New-Object Net.WebClient
    $WC.UseDefaultCredentials = $true
    $WC.Proxy.Credentials = $WC.Credentials
    $WC.DownloadString($URL)
}

#Proxy4
function Proxy4 {
    Param($URL);
    $WC = New-Object System.Net.WebClient
    $WC.Proxy = [System.Net.WebRequest]::DefaultWebProxy
    $WC.Proxy.Credentials = [System.Net.CredentialCache]::DefaultNetworkCredentials
    $WC.DownloadString($URL)
}

$URL = ""

if (NoProxy $URL -ne $null) {
    Write-Host "NoProxy works!"
} else {
    Write-Host "NoProxy failed!"
}

if (Proxy1 $URL -ne $null) {
    Write-Host "Proxy1 works!"
} else {
    Write-Host "Proxy1 failed!"
}

if (Proxy2 $URL -ne $null) {
    Write-Host "Proxy2 works!"
} else {
    Write-Host "Proxy2 failed!"
}

if (Proxy3 $URL -ne $null) {
    Write-Host "Proxy3 works!"
} else {
    Write-Host "Proxy3 failed!"
}

if (Proxy4 $URL -ne $null) {
    Write-Host "Proxy4 works!"
} else {
    Write-Host "Proxy4 failed!"
}