Hello,
I have HoMM1 installed from gog and Windows 11.
My pointer inside game is just a square that reverses colors underneath.
The pointer is not showed on printscreens so I can't provide any.

I've found topic tilted "HOMM 1 mouse pointer issue" (I can't post a link) with same problem, but there is no solution in it.

Hey Man, did You found any solution to that problem? I have the same after Windows 11 newest update...it was all ok before so I don't know what happened here...

First, GOG version is outdated DOS variant, instead of native Windows9x\Me\2k version doe to easiest way to make most compatible release. That usual thing for GOG DosBox releases (as well as custom builds of ScummVM bundled games - rip versions. they all)(only Heroes 2 come in two variants on GOG, and X-Com 2 is bundled with win-exe although there is no link for it).
Second, GOG DosBox releases use wrong exe for the desktop links.

There is launcher for it that have few settings. Try to change something of it, output\graphics mode first of.
overlay\surface or opengl. Sometiing like taht - esperiment with it.

Never un-check keep aspect ratio, keep it enabled

Launch game from that launcher.

(ofc no program files as install path, or setting wont saved)
http://www.gog.com/upload/forum/2022/10/fca67232ff4388c749de70ffb2f7b90a61def15d.png