>>The application is running on about 60 machines at same time so how I do it?
>

If you don't have to support Windows 95/98/ME, you can look for any 6008 events in the event log when the system last booted, which is itself marked with a 6005 event - 6008 indicates a unexpected shutdown, as opposed to 6006 which is logged for a clean shutdown - there's a KB article about these events. It would be quite easy to use WMI from VFP to determine this by comparing the times of the latest 6005/6009, 6006, and 6008, entries, if you want I could help with that..