param(
    [string]$TargetUser = 'user'
)

[Console]::OutputEncoding = [Text.Encoding]::UTF8
$ErrorActionPreference = 'Stop'

# Resolve target user's SID
try {
    $sid = (New-Object System.Security.Principal.NTAccount($TargetUser)).Translate([System.Security.Principal.SecurityIdentifier]).Value
} catch {
    throw "Unable to resolve SID for user '$TargetUser': $_"
}

$ntuserDat = "C:\Users\$TargetUser\NTUSER.DAT"
$hivePath  = "HKEY_USERS\$sid"
$regBase   = "Registry::$hivePath"

$hiveLoaded = Test-Path $regBase
$weLoaded   = $false

if (-not $hiveLoaded) {
    if (-not (Test-Path $ntuserDat)) { throw "NTUSER.DAT not found: $ntuserDat" }
    Write-Host "[*] User hive not loaded. Loading $ntuserDat as $hivePath"
    & reg.exe load $hivePath $ntuserDat | Out-Null
    if ($LASTEXITCODE -ne 0) { throw "reg load failed ($LASTEXITCODE). Is the user logged in?" }
    $weLoaded = $true
} else {
    Write-Host "[*] User hive already loaded at $hivePath (user may be logged in)"
}

function Set-UV {
    param([string]$SubPath, [string]$Name, $Value, [string]$Type = 'DWord')
    $full = "$regBase\$SubPath"
    if (-not (Test-Path $full)) { New-Item -Path $full -Force | Out-Null }
    New-ItemProperty -Path $full -Name $Name -Value $Value -PropertyType $Type -Force | Out-Null
    Write-Host ("    {0}\{1} = {2}" -f $SubPath, $Name, $Value)
}

try {
    Write-Host "[*] Applying Explorer / Taskbar / Theme settings"
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced'  'HideFileExt'         0
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced'  'Hidden'              1
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced'  'TaskbarAl'           0
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced'  'ShowTaskViewButton'  0
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced'  'LaunchTo'            1
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Themes\Personalize' 'AppsUseLightTheme'    0
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\Themes\Personalize' 'SystemUsesLightTheme' 0

    Write-Host "[*] Applying search / Bing / highlights settings"
    Set-UV 'Software\Policies\Microsoft\Windows\Explorer'                  'DisableSearchBoxSuggestions' 1
    Set-UV 'Software\Microsoft\Windows\CurrentVersion\SearchSettings'      'IsDynamicSearchBoxEnabled'   0

    Write-Host "[*] Applying Spotlight settings"
    Set-UV 'Software\Policies\Microsoft\Windows\CloudContent'              'DisableSpotlightCollectionOnDesktop' 1
    Set-UV 'Software\Policies\Microsoft\Windows\CloudContent'              'DisableWindowsSpotlightFeatures'     1

    Write-Host ""
    Write-Host "[OK] UI settings written to $hivePath"
}
finally {
    if ($weLoaded) {
        # Release any handles we might be holding on to
        [GC]::Collect(); [GC]::WaitForPendingFinalizers()
        [GC]::Collect(); [GC]::WaitForPendingFinalizers()
        Start-Sleep -Milliseconds 500
        & reg.exe unload $hivePath 2>&1 | Out-Null
        if ($LASTEXITCODE -eq 0) {
            Write-Host "[*] Unloaded $hivePath"
        } else {
            Write-Host "[!] reg unload returned $LASTEXITCODE — hive may still be held. Check with: reg query HKU\$sid"
        }
    }
}

Write-Host ""
Write-Host "Note: changes take effect when '$TargetUser' next logs in, or after explorer.exe restart if already logged in."