Account Expiration Default Value for "Never"

almarlibetario 

To set Account Expiry Date as Never, you better use the Clear-ADAccountExpiration cmdlet or you need to set accountExpires attribute value to 0.

Clear-ADAccountExpiration -Identity 'UserName'

----or----

function Get-ADUserFN( [string]$samid=$env:username){
     $searcher=New-Object DirectoryServices.DirectorySearcher
     $searcher.Filter="(&(objectcategory=person)(objectclass=user)(sAMAccountname=$samid))"
     $user=$searcher.FindOne()
      if ($user -ne $null ){
          $user.getdirectoryentry()
     }
}

$user = Get-ADUserFN 'UserName'
$user.psbase.properties
$user.accountExpires = '0'
$user.SetInfo()

Note: I have not personally tested the above commands.