I'll say this: it's definitely a video card glitch; it can't handle the pixelization. Probably because it's an MX, and even more so, a GeForce 4 – it's too weak for Heroes... Let him change the video card. For example, a guy has a GeForce4Ti, and everything works fine on it, but a GeForce4MX produces glitches. And how much RAM does he have, and what processor?
He has 512MB of DDR1 RAM and an AMD Athlon 2000 XP+ 1667Mhz processor.
