Simple script to toggle HTTP proxy on Windows

proxy.ps1

#Requires -PSEdition Core

[CmdletBinding()]
param (
    [Parameter(ParameterSetName = "enable")]
    [switch]
    $On,
    [Parameter(ParameterSetName = "disable")]
    [switch]
    $Off,
    [Parameter(ParameterSetName = "enable", Position = 0, Mandatory = $true)]
    [string]
    $ProxyAddress,
    [Parameter(ParameterSetName = "enable", Position = 1)]
    [string]
    $ProxyPort = "3128",
    [Parameter(ParameterSetName = "enable")]
    [bool]
    $ProxyBypassInLAN = $true
)

if ($IsWindows -eq $true) {
    $ProgressPreferenceOld = $ProgressPreference
    $ProgressPreference = "Continue"

    if ($On) {
        [Environment]::SetEnvironmentVariable("http_proxy", "http://${ProxyAddress}:${ProxyPort}", [EnvironmentVariableTarget]::User)
        [Environment]::SetEnvironmentVariable("https_proxy", "http://${ProxyAddress}:${ProxyPort}", [EnvironmentVariableTarget]::User)
        Set-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyEnable -Value 1
        if ($ProxyBypassInLAN) {
            Set-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyOverride -Value "<local>"
        }
        Set-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyServer -Value "${ProxyHost}:${ProxyPort}"
    }
    
    if ($Off) {
        [Environment]::SetEnvironmentVariable("http_proxy", $null, [EnvironmentVariableTarget]::User)
        [Environment]::SetEnvironmentVariable("https_proxy", $null, [EnvironmentVariableTarget]::User)
        Set-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyEnable -Value 0
        Remove-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyOverride -ErrorAction SilentlyContinue
        Remove-ItemProperty -LiteralPath "HKCU:/Software/Microsoft/Windows/CurrentVersion/Internet Settings" -Name ProxyServer -ErrorAction SilentlyContinue
    }

    $ProgressPreference = $ProgressPreferenceOld
}