Ask your question here if you can’t find the answer in the FAQ.

Somewhere in the folder with my documents, presumably at the address c:\Users\Gosha\Documents\My Games\Heroes of Might and Magic V — Tribes of the East\Profiles\, there is a *.cfg file (most likely user.cfg). It contains almost all the game configuration settings. Look for it and change the value of setvar gfx_fullscreen = from 1 to 0. You can also try disabling shaders... setvar gfx_noshadows = from 0 to 1. In general, if you have some knowledge of English, there are many interesting things you can adjust there.