Windows Firewall Cleanup

windows-firewall-cleanup.ps1

# Remove rules for file paths that are no longer exist
#
# Usage: windows-firewall-cleanup.ps1 [-y]
#   use -y parameter to actually remove the rules
#
# Roughly based on:
# * https://gist.github.com/xbb/246529a0c91305d53d428e116249c4ba
# * https://web.archive.org/web/20260218161026/https://wangxiaohu.com/blog/?p=420
#
# Don't forget to run as admin and `Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass`

param(
    [switch]$y = $false
)

$removeArgs = if ($y) {
    @{ Verbose = $true }
} else {
    @{ WhatIf = $true }
}

$unusedFilters =
    Get-NetFirewallApplicationFilter |
    Where-Object {
        $program = [Environment]::ExpandEnvironmentVariables($_.Program)

        $_.Program -notin @("Any", "System") -and
        [System.IO.Path]::IsPathRooted($program) -and
        -not (Test-Path -LiteralPath $program -PathType Leaf)
    }

$unusedFilters |
    ForEach-Object { [Environment]::ExpandEnvironmentVariables($_.Program) } |
    Sort-Object -Unique

$unusedFilters | Remove-NetFirewallRule @removeArgs