killing threads

I'm trying to write a screen-saver that, after a certain amount of time, silently kills all currently running threads (programs), and logs out. The screen-saver code doesn't look too complicated, neither does the logging out. But getting programs to close silently (if un-saved documents are open, I just want to trash them, or somehow say "No" to the save dialogs) is the trick. Does anyone have any suggestions or knows of any information on this? MS's KB is a little thin (virtually non-existant) on this subject.

Thanks
Jon

just to clarify, when I refered to killing threads I mean all currently running programs, not just the threads I've created, like Word, Netscape, etc.

Thanks
Jon