Maybe instead of VFP you can look at restricting the installation of software (such as games) by using something like WinNT Workstation.

> I am developing Application that manage the acess control of PC using VFP. It work for Windows, but I faced the problem to Notice, Interrupt and LOCK the screen of PC if user is playing GAME such as Age of Empire, and so on. How could I interrupt these games to notice user that their usage time is finish without terminate the game either?