Hi;

I try to play with Heroes of Might and Magic® 5: Bundle on my desktop computer (Core I7 6700k Windows 10 Professional19041.630) but it seems that the game freezes after the splash screen.
Is this game working with a 64 bits OS?
Do I configure something before running?

It works just fine for me.

Check if you have DirectX 9.0c installed manually: https://cncnz.com/features/technical-support-help-guides/installing-directx-90c/

Thank you. I have DX12 installed and I found something else on Reddit:

FIX FOUND:

Alright so this has been affecting A LOT of Heroes games. I helped out OP with this and it is now working like a charm.

I've had this same issue with Heroes VI, and I fixed that too, so if you have a similar issue with any other heroes game, here's how you fix it:

1: Find the executable file (.exe file) that you use to play the game.
2: Right-Click on this executable file.
3: Click on "Properties"
4: Click on "Compatibility"
5: Check: "Disable fullscreen optimizations"

And done! This is how you fix the bug of heroes games not launching. This all started when Windows released it's last Windows 10 update and it seems to only affect Windows 10 users.

and it works!

Dx >10 never include Dx any up to 9. But that not a problem, cause it probably already installed with some games. Just download web-installer of DirectX and check updates manually (ofc download it only from Microsoft site, well something can be downloaded from Valve Steam - I guess it ok too just check updates).
Manually check updates for latest stable Win0 Build and for redists. VC Redists, Net Framework DirectX - they all can have updates not included in installers that you download from of site a d of course games installers use oldest versions.
Especially must be updated some old redists, installed by game. Sometimes it very differ from version even closet by version number. Check Installed/Uninstall applications menu in Windows to see what redists you have.

Enable/disable fullscreen optimisation and some other compatibility things are updated for Windows 8/10 long ago actually. And it work very different on differ OS. Some option available and for Win7 too.
And GOG - they previously always enable admin run, but stop doing this - now always set DPI scaling compatibility, that thing same as optimisation work differently on differ OS. And with some games.

When you install games - especially from GOG (Steam too) - check compatibility things on exe/bat/.etc files. Better doing that with Microsoft ACT tool (for Win up to 8) or with Windows ADK (for Win10). ADK - is a toolset.
If you want easy light app - check Verok (aka Verokster, author of GLwrapper's and mods, for Heroes M&M too) AppCompatibilityChecker (start that exe as admin). It show all compatibility, but cant remove some installed by GOG installers
http://drive.google.com/file/d/16ljD92B1jPIT_bi1bh3pppBVAudkIj4Y/view
Exe Properties in Windows never show all options. And in Win8/10 it initially have only adminrun in Properties. Still some checkboxes are missing.

Some compatibility set by Windows (7/8 , any else?) itself on first game run. Try to remove that too, and if it turn on again - forget it.
All compatibility can be viewed and removed (and enabled) in Win REGEDIT. But some installed by GOG use ACT tool sdb packages - that compatibility use some more Registry parts, as well as Windows system folder.