When writing PowerShell scripts that modify system settings, access protected resources, or perform administrative tasks, it's crucial to verify whether the script is running with elevated privileges. This prevents runtime errors and ensures proper functionality.

The most reliable way to check for admin rights is through the .NET framework's WindowsPrincipal class:

# Check if current user is admin
function Test-Administrator {
    $user = [Security.Principal.WindowsIdentity]::GetCurrent()
    (New-Object Security.Principal.WindowsPrincipal $user).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
}

# Usage example
if (-not (Test-Administrator)) {
    Write-Warning "Please run this script as Administrator!"
    exit 1
}

Another approach checks for the presence of the Administrator SID in the token:

function Test-IsAdmin {
    $identity = [System.Security.Principal.WindowsIdentity]::GetCurrent()
    $principal = New-Object System.Security.Principal.WindowsPrincipal($identity)
    $principal.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)
}

For legacy compatibility, you can verify admin rights through registry access attempts:

function Test-AdminWithRegistry {
    try {
        $null = Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion" -Name "ProgramFilesDir" -ErrorAction Stop
        return $true
    }
    catch {
        return $false
    }
}

• Always check privileges at script startup
• Provide clear error messages when elevation is needed
• Consider automatic elevation when possible
• Document privilege requirements in your script's help

When admin rights are required but missing, you can relaunch the script:

if (-not (Test-Administrator)) {
    $arguments = "& '" + $myinvocation.mycommand.definition + "'"
    Start-Process powershell -Verb RunAs -ArgumentList $arguments
    exit
}

When writing PowerShell scripts that modify system settings or access protected resources, it's crucial to verify whether the script is running with elevated privileges. Many operations in Windows require administrator rights, and attempting them without proper permissions will result in errors.

The most reliable method to check for admin rights involves examining the current security principal:

# Check if running as administrator
function Test-IsAdmin {
    $currentPrincipal = New-Object Security.Principal.WindowsPrincipal([Security.Principal.WindowsIdentity]::GetCurrent())
    return $currentPrincipal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
}

if (-not (Test-IsAdmin)) {
    Write-Warning "This script requires administrator privileges!"
    exit 1
}

For scenarios where you need different approaches, consider these alternatives:

# Method 1: Using net session
try {
    net session > $null 2>&1
    $true
} catch {
    $false
}

# Method 2: Checking process elevation
(Get-Process -Id $PID).StartInfo.Verb -eq "runas"

When admin rights are needed but not present, you can prompt for elevation:

if (-not (Test-IsAdmin)) {
    Start-Process -FilePath "powershell" -ArgumentList "-NoProfile -ExecutionPolicy Bypass -File `"$($MyInvocation.MyCommand.Path)`"" -Verb RunAs
    exit
}

Be aware of these potential issues:

• False positives in certain virtualization environments
• UAC settings affecting elevation behavior
• Group Policy restrictions on script execution

Follow these guidelines for robust privilege checking:

• Perform the check early in your script
• Provide clear feedback to users about privilege requirements
• Consider implementing graceful fallback behavior
• Document privilege requirements in your script's help