Severe lag in the game.

Hello, I have a problem in Heroes 4: When I select the resolution 1280x1024 in the game, on large maps, there are severe slowdowns. When moving the mouse, the animation is jerky, and the troops also move in a choppy manner. If I uncheck "display animation" or set the game resolution lower, everything becomes perfect. But it can't be that in 2017, an old game can't run properly at a resolution of at least 1280x1024? I've already tried everything...

Windows 7.
Processor - Athlon X4 Quad-core 651 3.0 Ghz
Video card - Geforce 550 TI 1gb.
RAM - 8 gb.

I reinstalled Windows a couple of months ago.
If anyone can help, I would be very grateful.

I recorded a video for clarity, although the screen capture program is a bit clunky, but it doesn't change the essence. https://www.youtube.com/watch?v=aEE1QTWO7wA

Everything is visible in the video.
Firstly, there is a problem in the game that it puts a very heavy load on the processor if you enable pixel centralization.
Pixel centralization is when, when choosing a higher or lower resolution compared to the standard, the image does not shift to the side, but simply stretches and reduces the texture size to the required one. In this case, only the processor works, the video card is not involved. In fact, if you have Windows 7, the compatibility should be set to XP - because - yes, you guessed it - pixel centralization puts much less load on the processor in it. It is possible to disable centralization through the game's configuration files, but then you simply won't see anything.
Secondly, you need to play in full-screen mode. In the properties, select "Disable Windows Aero when starting the game." This will at least reduce the load by half.
Thirdly, please, I ask you to send what is shown in the "Task Manager" regarding this process - just show all the windows, then I will understand the essence.
Fourthly, install all the patches as an administrator. This sometimes completely replaces all the game files, not partially.
Also, send your game build - do you have "Complete Collection" or "Gold Collection" - then it will be clearer. By the way, surprisingly, it is better to install a pirated version - they almost always have an in-file compatibility with XP, which, as I said, helps a lot.