>From that form I create another Top-Level form and I do .Show of that form. When I close that form, on form with menu if the first was MENU1.MPR now it has changed in MENU2.MPR and otherwise.
>Why does this happening and how can I fix this, so that I always have the menu which it was before showing of another form.

After reading replies, it's possible you've discovered a small, unusual bug, or else there's something not right in your code, one of those 2 things must be (but what you're doing is not commonly done, so hard to say).

You might test what's going on by creating a 3rd menu, and not trying to do any "switching" of menus at all on the 1st TL, and then maybe using the new menu on the 2nd TL. Just to see what happens, try to isolate the problem.

Basic troubleshooting, is all...