Nadya,
Was the machine swapping to disk? If it was then it was still running and not hung. VFP may very well show "Not responding" during this time because it's not handling normal windows events while it's inside a single VFP statement.
>Why not? 20 min. for the first operation - how should I call it? It showed "Not responding", when I hit Ctrl+Alt+Del
>
>At work first and second operations worked. It hung on the last one.