Question

How do I disable UAC using a PowerShell script? I can do this manually via the registry using the adding the following registry entry

Key:   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA
Value: 0
Type:  DWORD

The script should account for the possibility that this key is already present and set incorrectly.

Answer 1

1 – Add the following two functions to your PowerShell profile (C:\Windows\System32\WindowsPowerShell\v1.0\profile.ps1)

2 – Run Disable-UAC in PowerShell

3 – Reboot for changes to take effect. Using PowerShell, this would be Restart-Computer -Force -Confirm:$false

Function Test-RegistryValue 
{
    param(
        [Alias("RegistryPath")]
        [Parameter(Position = 0)]
        [String]$Path
        ,
        [Alias("KeyName")]
        [Parameter(Position = 1)]
        [String]$Name
    )

    process 
    {
        if (Test-Path $Path) 
        {
            $Key = Get-Item -LiteralPath $Path
            if ($Key.GetValue($Name, $null) -ne $null)
            {
                if ($PassThru)
                {
                    Get-ItemProperty $Path $Name
                }       
                else
                {
                    $true
                }
            }
            else
            {
                $false
            }
        }
        else
        {
            $false
        }
    }
}

Function Disable-UAC
{
    $EnableUACRegistryPath = "REGISTRY::HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System"
    $EnableUACRegistryKeyName = "EnableLUA"
    $UACKeyExists = Test-RegistryValue -RegistryPath $EnableUACRegistryPath -KeyName $EnableUACRegistryKeyName 
    if ($UACKeyExists)
    {
        Set-ItemProperty -Path $EnableUACRegistryPath -Name $EnableUACRegistryKeyName -Value 0
    }
    else
    {
        New-ItemProperty -Path $EnableUACRegistryPath -Name $EnableUACRegistryKeyName -Value 0 -PropertyType "DWord"
    }
}