Heroes 3 issues under XP or Vista.

There is no Remote.cpp, just like there is no Hero3.prj. Something is wrong here; why is it referencing an error in a non-existent file? Perhaps it needs this file to be provided?
However, I found this remote.cpp in the computer's files, and it seems to be written in C++.

:smile52: :smile52: :smile52:... aemghmk... I apologize... mdyam.

No, this file is in pure English and states that it is part of the WinLIRC package, which was taken from LIRC (apparently, documentation from a software package for some infrared remote control).
It says that this software is free software and can be freely distributed and/or modified because it falls under the GNU GPL license, etc., etc. I don't think it makes sense to write any further about what else it says. But regarding your problem with HoMM and Vista, I assure you that this file has absolutely nothing to do with it.

Windows is most likely complaining about some other Remote.cpp, probably a system file of Windows itself. It might not even be a separate file, but rather some function in a system library.

And honestly, I don't even know how I can help you in this case... but I know something that might ;). It's called Google! But I still think that you simply installed something incorrectly.
Have you tried installing the game, specifically this version, on other systems/machines? Does it work? It's also possible that it's a bug in Windows itself, because it's something that will glitch and won't tell you properly why it's glitching.
Try reinstalling Windows. That's the only way - seven troubles, one solution - reinstallation, :D. There's nothing else you can do. That's how people solve problems with it.