Posts from The aspect ratio is displayed incorrectly.

Hello everyone.
The problem is that the screen aspect ratio is displayed as if on a 4:3 monitor, but stretched to the sides (I currently have a widescreen 2560x1440 monitor). I tried using a tweaker and changing it manually, but it doesn't help. What else can I do?
When I installed the game, I had a 4:3 monitor, and then I deleted it, but I kept the saves because I had almost completed the game on the highest difficulty. Now I decided to finish it, and this problem appeared. In the game, if I change the resolution, there is such an option, and the image becomes clearer, but not proportionally. What should I do?

Then another question, in which files are the campaign saves and campaign progress stored? I need to transfer them in such a way that the old monitor settings are not transferred, and the game will then set them according to the new monitor, as happened in the original game, where the saves were not important.

Settings and saves for the original game and the add-ons are stored in different locations. For example, for Tribes of the East, they are located at \User Documents\My Games\Heroes of Might and Magic V — Tribes of the East\saves.
The settings file is also located there: user.cfg for the original game, and user_a1, user_a2 for the add-ons.
However, there's no point in these manipulations, as the proportions in widescreen mode will be distorted everywhere except for Tribes of the East with patch 3.1. No matter how you adjust the settings, they are stored within the executable file.
There is an option to play the old campaigns using Tribes of the East 3.1, but you will need to download a mod to unlock the previous campaigns and play without distortions.

Could you please tell me if the artifacts collected during a mission are carried over to the next mission when playing the campaigns transferred from previous parts of Heroes V into Tribes of the East?

No, they don't transfer.