Remove-AutoConfigProxy.ps1

<#
.SYNOPSIS
	This script nullifies the AutoConfigURL registry value in the HKCU hive for the current and all
	other users.  This removes the auto configuration proxy URL value in IE.
.NOTES
	Created on: 	5/7/2015
	Created by: 	Adam Bertram
	Filename:		Remove-AutoConfigProxy.ps1			
.EXAMPLE
	PS> .\Remove-AutoConfigProxy.ps1

	This nullifies the AutoConfigURL HKCU registry value for the current and all other user profiles to
	remove the IE auto configuration URL.
	
#>
[CmdletBinding()]
param ()
begin {
	$ErrorActionPreference = [System.Management.Automation.ActionPreference]::Stop
	Set-StrictMode -Version Latest
	
	function Get-LoggedOnUserSID {
		<#
		.SYNOPSIS
			This function queries the registry to find the SID of the user that's currently logged onto the computer interactively.
		#>
		[CmdletBinding()]
		param ()
		process {
			try {
				if (-not (Get-PSDrive -Name HKU -ErrorAction SilentlyContinue)) {
					New-PSDrive -Name HKU -PSProvider Registry -Root Registry::HKEY_USERS | Out-Null
				}
				(Get-ChildItem HKU: | where { $_.Name -match 'S-\d-\d+-(\d+-){1,14}\d+$' }).PSChildName
			} catch {
				Write-Warning -Message "$($_.Exception.Message) - Line Number: $($_.InvocationInfo.ScriptLineNumber)"
			}
		}
	}
	
	function Set-RegistryValueForAllUsers {
	    <#
		.SYNOPSIS
			This function sets a registry value in every user profile hive.
		.EXAMPLE
			PS> Set-RegistryValueForAllUsers -RegistryInstance @{'Name' = 'Setting'; 'Type' = 'String'; 'Value' = 'someval'; 'Path' = 'SOFTWARE\Microsoft\Windows\Something'}
		
			This example would modify the string registry value 'Type' in the path 'SOFTWARE\Microsoft\Windows\Something' to 'someval'
			for every user registry hive.
		.PARAMETER RegistryInstance
		 	A hash table containing key names of 'Name' designating the registry value name, 'Type' to designate the type
			of registry value which can be 'String,Binary,Dword,ExpandString or MultiString', 'Value' which is the value itself of the
			registry value and 'Path' designating the parent registry key the registry value is in.
		.PARAMETER Remove
			A switch parameter that overrides the default setting to only change or add registry values.  This removes one of more registry keys instead.
			If this parameter is used the only required key in the RegistryInstance parameter is Path.  This will automatically remove both
			the x86 and x64 paths if the key is a child under the SOFTWARE key.  There's no need to specify the WOW6432Node path also.
		.PARAMETER Force
			A switch parameter that is used if the registry value key path doesn't exist will create the entire parent/child key hierachy and creates the 
			registry value.  If this parameter is not used, if the key the value is supposed to be in does not exist the function will skip the value.
		#>
		[CmdletBinding()]
		param (
			[Parameter(Mandatory = $true)]
			[hashtable[]]$RegistryInstance,
			[switch]$Remove
		)
		begin {
			if (-not (Get-PSDrive -Name HKU -ErrorAction SilentlyContinue)) {
				New-PSDrive -Name HKU -PSProvider Registry -Root Registry::HKEY_USERS | Out-Null
			}
		}
		process {
			try {
				## Change the registry values for the currently logged on user
				$LoggedOnSids = Get-LoggedOnUserSID
				if ($LoggedOnSids -is [string]) {
					Write-Verbose -Message "Found 1 logged on user SID"
				} else {
					Write-Verbose -Message "Found $($LoggedOnSids.Count) logged on user SIDs"
				}
				foreach ($sid in $LoggedOnSids) {
					Write-Verbose -Message "Loading the user registry hive for the logged on SID $sid"
					foreach ($instance in $RegistryInstance) {
						if ($Remove.IsPresent) {
							Write-Verbose -Message "Removing registry key '$($instance.path)'"
							Remove-Item -Path "HKU:\$sid\$($instance.Path)" -Recurse -Force -ea 'SilentlyContinue'
						} else {
							if (!(Get-Item -Path "HKU:\$sid\$($instance.Path)" -ea 'SilentlyContinue')) {
								Write-Verbose -Message "The registry key HKU:\$sid\$($instance.Path) does not exist.  Creating..."
								New-Item -Path "HKU:\$sid\$($instance.Path | Split-Path -Parent)" -Name ($instance.Path | Split-Path -Leaf) -Force | Out-Null
							} else {
								Write-Verbose -Message "The registry key HKU:\$sid\$($instance.Path) already exists. No need to create."
							}
							Write-Verbose -Message "Setting registry value $($instance.Name) at path HKU:\$sid\$($instance.Path) to $($instance.Value)"
							
							Set-ItemProperty -Path "HKU:\$sid\$($instance.Path)" -Name $instance.Name -Value $instance.Value -Type $instance.Type -Force
						}
					}
				}
				
				foreach ($instance in $RegistryInstance) {
					if ($Remove.IsPresent) {
						if ($instance.Path.Split('\')[0] -eq 'SOFTWARE' -and ((Get-Architecture) -eq 'x64')) {
							$Split = $instance.Path.Split('\')
							$x86Path = "HKCU\SOFTWARE\Wow6432Node\{0}" -f ($Split[1..($Split.Length)] -join '\')
							$CommandLine = "reg delete `"{0}`" /f && reg delete `"{1}`" /f" -f "HKCU\$($instance.Path)", $x86Path
						} else {
							$CommandLine = "reg delete `"{0}`" /f" -f "HKCU\$($instance.Path)"
						}
					} else {
						## Convert the registry value type to one that reg.exe can understand
						switch ($instance.Type) {
							'String' {
								$RegValueType = 'REG_SZ'
							}
							'Dword' {
								$RegValueType = 'REG_DWORD'
							}
							'Binary' {
								$RegValueType = 'REG_BINARY'
							}
							'ExpandString' {
								$RegValueType = 'REG_EXPAND_SZ'
							}
							'MultiString' {
								$RegValueType = 'REG_MULTI_SZ'
							}
							default {
								throw "Registry type '$($instance.Type)' not recognized"
							}
						}
						if (!(Get-Item -Path "HKCU:\$($instance.Path)" -ea 'SilentlyContinue')) {
							Write-Verbose -Message "The registry key 'HKCU:\$($instance.Path)'' does not exist.  Creating..."
							New-Item -Path "HKCU:\$($instance.Path) | Split-Path -Parent)" -Name ("HKCU:\$($instance.Path)" | Split-Path -Leaf) -Force | Out-Null
						}
						if (-not $instance.Value) {
							$instance.Value = '""'
						}
						$CommandLine = "reg add `"{0}`" /v {1} /t {2} /d {3} /f" -f "HKCU\$($instance.Path)", $instance.Name, $RegValueType, $instance.Value
					}
					Set-AllUserStartupAction -CommandLine $CommandLine
				}
			} catch {
				Write-Warning -Message "Error: $($_.Exception.Message) - Line Number: $($_.InvocationInfo.ScriptLineNumber)"
				$false
			}
		}
	}
	
	function Set-AllUserStartupAction {
	<#
	.SYNOPSIS
		A function that executes a command line for the any current logged on user and uses the Active Setup registry key to set a 
		registry value that contains a command line	EXE with arguments that will be executed once for every user that logs in.
	.PARAMETER CommandLine
		The command line string that will be executed once at every user logon
	#>
		[CmdletBinding()]
		param (
			[Parameter(Mandatory = $true)]
			[string]$CommandLine
		)
		process {
			try {
				## Create the Active Setup registry key so that the reg add cmd will get ran for each user
				## logging into the machine.
				## http://www.itninja.com/blog/view/an-active-setup-primer
				$Guid = [guid]::NewGuid().Guid
				Write-Verbose -Message "Created GUID '$Guid' to use for Active Setup"
				$ActiveSetupRegParentPath = 'HKLM:\Software\Microsoft\Active Setup\Installed Components'
				New-Item -Path $ActiveSetupRegParentPath -Name $Guid -Force | Out-Null
				$ActiveSetupRegPath = "HKLM:\Software\Microsoft\Active Setup\Installed Components\$Guid"
				Write-Verbose -Message "Using registry path '$ActiveSetupRegPath'"
				Write-Verbose -Message "Setting command line registry value to '$CommandLine'"
				Set-ItemProperty -Path $ActiveSetupRegPath -Name '(Default)' -Value 'All Users Startup Action' -Force
				Set-ItemProperty -Path $ActiveSetupRegPath -Name 'Version' -Value '1' -Force
				Set-ItemProperty -Path $ActiveSetupRegPath -Name 'StubPath' -Value $CommandLine -Force
				Write-Verbose -Message 'Done'
			} catch {
				Write-Warning -Message "Error: $($_.Exception.Message) - Line Number: $($_.InvocationInfo.ScriptLineNumber)"
				$false
			}
		}
	}
}

process {
	try {
		$Instance = @{
			'Name' = 'AutoConfigURL';
			'Type' = 'String';
			'Path' = 'SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings';
			'Value' = ''
		}
		Set-RegistryValueForAllUsers -RegistryInstance $Instance
	} catch {
		Write-Error "$($_.Exception.Message) - Line Number: $($_.InvocationInfo.ScriptLineNumber)"
	}
}