Dear all,    My program works fine under 2000 and XP, but not NT4.0. I found that    GetLastInputInfo only support Win2000 or above from the article http://delphi.ktop.com.tw/topic.php?topic_id=46310. If my program need to check idle time for NT4 platform, is there any similar API that work? Furthermore, my program need to support NT4, Win2000 and WinXP indeed, is there any API that work fine in those platform? Thanks for any reply. Mark Leung