Potentially. The page you linked literally doesn't define the range that the single file falls into.
Fanboi harder.

If you're going to be this paranoid, remove anything on your computer not made by Microsoft since it POTENTIALLY might have something fishy in it.

I've seen projects made by people I've known for years flagged as suspicious (not even harmful) by antiviruses by mistake. This happens more often than you'd think, but then again you'd have to actually have experience with computers and games to know that.

Hi guys, is there a way to synchronize save files from HotA in the GOG galaxy launcher?

Docent Picolan, the founder and leader of the Horn of the Abyss project, has passed away: http://heroescommunity.com/viewthread.php3?TID=39830&PID=1532555#focus

The installer won't let me install the mod due to the folder the game is kept in. This even though the HD mod went in with little issue. Do I really have to uninstall everything and reinstall it elsewhere to get this to work?

Just wanted to pop in and say how freaking amazing and underrated this mod is. Indistinguishable as a 'non-official' expansion, it fits perfectly. Amazing, can't wait for more.

Did you figure it out? Having the same issue

In the very first post of this thread it states "Install on UNMODIFIED version". HotA already has HD mod included. My guess is that it's failing because of this.

It is mentioned on the HotA page that it should have no problems running with the HD mod already installed. And this is that it refuses to install due to the folder the game is kept in.

edited

Just installed Horn of the Abyss today and i ran into the issue that i could not install in the C:\Program Files (x86)\GOG Galaxy\Games\HoMM 3 Complete

however by copying the whole game to a folder i made in
C:\Users\Name\Games which i called Horn of the Abyss i could install without any issues, during installation it said that it could not find the game files however after installing it could run the game just fine.

I ran into the same issue in not being able to install HotA with HoMM3 Complete under the Programs folder (where my GOG games are normally).

So what I did instead was uninstalled Complete and installed it under my 'Games' folder under my C:/ drive and then HotA installed fine.

It apparently does not like installing to games that are kept under a "Programs" folder, which GOG defaults to.