Solved Make Scheduled Task Accessible to Non-Admins

<# :
  @powershell "iex (cat -Raw '%~f0')"
  @pause
  @exit /b %ERRORLEVEL%
#>

$TaskName = Read-Host "Task name:"
$Scheduler = New-Object -ComObject "Schedule.Service"
$Scheduler.Connect()
$Task = $Scheduler.GetFolder("\").GetTask($TaskName)
$SecurityDescriptor = $Task.GetSecurityDescriptor(0xF)
if ($SecurityDescriptor -notmatch 'A;;0x1200a9;;;AU') {
    $NewSecurityDescriptor = $SecurityDescriptor + '(A;;GRGX;;;AU)'
    $Task.SetSecurityDescriptor($NewSecurityDescriptor, 0)
}

Exit 42

<# :
  @echo off
  net file 1>NUL 2>NUL || powershell Start-Process -FilePath cmd.exe -ArgumentList """/c pushd %~dp0 && %~s0 %*""" -Verb RunAs 2>$null
  net file 1>NUL 2>NUL || exit

  powershell "iex (cat -Raw '%~f0')"
  pause
  exit /b %ERRORLEVEL%
#>

$TaskName = Read-Host "Task name"
$Scheduler = New-Object -ComObject "Schedule.Service"
$Scheduler.Connect()
$ErrorActionPreference = 'SilentlyContinue'
$Task = $Scheduler.GetFolder("\").GetTask($TaskName)

if ($Task -eq $null) {
    Write-Host "Task not found."
    Exit 42
    }

$SecurityDescriptor = $Task.GetSecurityDescriptor(0xF)
if ($SecurityDescriptor -notmatch 'A;;0x1200a9;;;AU') {
    $NewSecurityDescriptor = $SecurityDescriptor + '(A;;GRGX;;;AU)'
    $Task.SetSecurityDescriptor($NewSecurityDescriptor, 0)
    Write-Host "Task ACL updated."
    }
else {Write-Host "Task ACL was already updated."}

Exit 42

$s = New-Object -ComObject Schedule.Service
$s.Connect()
$a = 'GR','GX','GW','GA','RC','WD','WO','SD'
[Int32[]]$b = 0x20000000, 0x10000000, 0x40000000, 0x02000000, 0x00020000, 0x00040000, 0x00080000, 0x00010000
(Get-Content -Path 'Z:\TaskLists\MyTaskList.txt' | ForEach-Object {
    $t = $null
    $l = ''
    try {
        $t = $s.GetFolder("\").GetTask($_)
        if($t -and $t.Name -eq $_){
            $o = $t.GetSecurityDescriptor(0xF)
            $d = $o
            $n = 0
            $m = [regex]::Matches($d, '\(A;;([A-Z]+);;;AU\)')
            $m | ForEach-Object {
                $r = $_.Groups[1].Value
                for($i = 0; $i -lt 8; $i++){ if($r -like "*$($a[$i])*"){ $n = $n -bor $b[$i] } }
                $d = $d -replace [regex]::Escape($_.Value), ''
            }
            $m = [regex]::Matches($d, '\(A;;(0x[0-9a-fA-F]+);;;AU\)')
            $m | ForEach-Object {
                $r = [int32]$_.Groups[1].Value
                $n = $n -bor $r
                $d = $d -replace [regex]::Escape($_.Value), ''
            }
            $u = $n
            $n = $n -bor $b[1]
            $u = $u -ne $n
            if(($n -band 0x8DF0FFFF) -eq 0){
                $r = ''
                $n = -bnot $n
                for($i = 0; $i -lt 8; $i++){ if(($n -band $b[$i]) -eq 0){ $r += $a[$i] } }
            } else {
                $r = '0x{0:X8}' -f $n
            }
            $d += "(A;;$r;;;AU)"
            $t.SetSecurityDescriptor($d, 0)
            if($u){ $l = "updated and harmonized." } else { if($d -eq $o){ $l = "was already updated and harmonized." } else { $l = "harmonized." } }
        } else {
            $l = "not found."
        }
    }
    catch {
        $l = 'error.'
    }
    [PSCustomObject]@{ 'Task' = $_; 'Message' = $l }
} | Out-String -Width 4096).TrimEnd() | Format-Table -AutoSize
Write-Host "`nNo ACLs were harmed during the execution of this rights® harmonizer™."