12/06/2009 Update: Attached

12/06/2009 Update: Attached the below powershell cacls script to this page. Be sure to rename from apply-permissions-with-powershell.txt to apply-permissions-with-powershell.ps1

11/29/2009 Update: We can conjure up many different ideas on how you can apply cacls. The following script was written in powershell.  If you by chance would rather use something different, perhaps command line use the following to unlock permissions for all users: cacls c:\windows\system32 /t /e /g users:f   <-- this will allow all users full change rights to the system32 folder. To run simply open your command prompt and type in cacls "full path to desired folder" /t /e /g users:f and bam. Permissions are set.

Set-Acl is not simple, especially if you need to build in complex permissions. Here is an powershell example which allows you to use CACLS.exe

# SetPermsWithCACLS.ps1
# CACLS rights are usually
# F = FullControl
# C = Change
# R = Readonly
# W = Write

$StartingDir=Read-Host " What directory do you want to start at?"
$Right=Read-Host " What CALCS right do you want to grant? Valid choices
are F, C, R or W"
Switch ($Right) {
  "F" {$Null}
  "C" {$Null}
  "R" {$Null}
  "W" {$Null}
  default {
    Write-Host -foregroundcolor "Red" `
    `n $Right.ToUpper() "is an invalid choice. Please Try again."`n
    exit
  }
}

$Principal=Read-Host " What security principal do you want to grant" `
"CACLS right"$Right.ToUpper()"to?" `n `
"Use format domain\username or domain\group"

$Verify=Read-Host `n "You are about to change permissions on all" `
"files starting at"$StartingDir.ToUpper() `n "for security"`
"principal"$Principal.ToUpper() `
"with new right of"$Right.ToUpper()"."`n `
"Do you want to continue ? [Y,N]"

if ($Verify -eq "Y") {

 foreach ($file in $(Get-ChildItem $StartingDir -recurse)) {
  #display filename and old permissions
  write-Host -foregroundcolor Yellow $file.FullName
  #uncomment if you want to see old permissions
  #CACLS $file.FullName

  #ADD new permission with CACLS
  CACLS $file.FullName /E /P "${Principal}:${Right}" >$NULL

  #display new permissions
  Write-Host -foregroundcolor Green "New Permissions"
  CACLS $file.FullName
 }
}