powershell reset AD password every 2 hours

$logPath="C:\inetpub\changePwd_log.txt"
"=============" + [DateTime]::Now.ToString() + "=============" | Out-File -FilePath $logPath -Append

$sysUsers=",administrator,spadmin,joh,guest,Uwe Kukla,krbtgt,"
#$strFilter = "(&(objectCategory=User)(Department=Finance))"
$strFilter = "(&(objectCategory=User))"
$objDomain = New-Object System.DirectoryServices.DirectoryEntry

$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = $objDomain
$objSearcher.PageSize = 1000
$objSearcher.Filter = $strFilter
$objSearcher.SearchScope = "Subtree"

$colProplist = "name"
foreach ($i in $colPropList)
    {
    #    $objSearcher.PropertiesToLoad.Add($i)
    }


$colResults = $objSearcher.FindAll()

foreach ($objResult in $colResults)
    {
    $objItem = $objResult.Properties;
    #$objItem.name
    if($sysUsers.tolower().contains("," + $objItem.name[0].tolower() + ","))
    {
        continue;
    }


    $now=[DateTime]::Now.AddHours(-2)
    #$now=[DateTime]::Now.AddMinutes(-2)
    #$dt=[datetime]::FromFileTimeUtc($objItem.properties.pwdlastset.value)
    $dt=[datetime]::fromfiletime($objItem.pwdlastset[0])
    #write-host($objItem.name[0])
    #if($objItem.name[0].ToLower().Equals("test4"))
    #{
    #    write-host($objItem.name[0] + "    " + $dt + "    " + $now)
    #}
    if($now -gt $dt)
    {
        $secure = convertto-securestring "Abaa11" -asplaintext -force
        #write-host($objItem.distinguishedname[0])
        #Set-ADAccountPassword -Identity $objItem.name[0] -NewPassword $secure -reset
        Set-ADAccountPassword -Identity $objItem.distinguishedname[0] -NewPassword $secure -reset
        #write-host($objItem.name[0] + "    " + $dt.tostring())    
        $objItem.name[0] + "    " + $dt.tostring() + "      " + [DateTime]::Now.tostring() | Out-File -FilePath $logPath -Append
    }
    ##Write-Host ([DateTime]::Now.AddHours(-2).ToString())
    #$objItem.pwdlastset
    }