Severe lag in the game.

The installed game can be easily transferred (without installation) from one computer to another and even run from a flash drive – as long as the files are not damaged. On my computer, the game is not on the main drive, but on a logical drive, so reinstalling Windows won't affect it. I'll try a pirated version – maybe it will actually allow me to use a resolution without full-screen mode. But I suspect the problem is related to the monitor – this issue didn't exist before widescreen monitors became common.