http://www.autoitscript.com/forum/topic/117633-how-to-add-to-path-environment
-variable-with-autoit/
官方論壇有，主要是做紀錄方便同好查詢
$key = "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session
Manager\Environment"
$val = "PATH"
$PATH = RegRead($key, $val)
$sAddThisPath = "C:\my new path\"
$PATH = $PATH & ";" & $sAddThisPath
RegWrite($key,$val,"REG_EXPAND_SZ",$PATH)
EnvUpdate()