There is a bug in Might and Magic IX.
Having searched around the internet for this problem, where people using Windows 7 or Vista get stuck at the loading screen, the only solution being so far was to Alt+Tab the game and then go back in.

However, I have finally found the root of the problem (99.9% sure).
Somehow, after having Alt+Tabbed out of the game and back in for hundreds of times, the small ship moving back and forth during the loading screen had disappeared. After that, all the loading screens never got stuck again and the game seemed perfect!

I am not good with modifying files or anything like that, so I have no idea how to "remove" this moving ship from appearing in the game (because after exiting the game and returning, the moving ship was still there, causing me to get stuck).

If anyone is capable of removing that ship from the game, and also teach me how to do it, then this theory of mine can be put to the test (even though I am certain that it's the moving ship that causes the glitch)