Recently I want to buy homm3 to enjoy this gem again,
but after doing some research I find this:

[url=http://www.gogwiki.com/wiki/Heroes_of_Might_and_Magic_3:_Complete_Edition]http://www.gogwiki.com/wiki/Heroes_of_Might_and_Magic_3:_Complete_Edition[/url]

it says "Heroes of Might and Magic 3 has shown to be rather unstable under Windows 7 and Windows Vista, even with the HDMod installed. Users should be aware of crashes that may happen after a few hours."

can you guys please confirm this for me?
since this is really a deal breaker for me, thank you so much.

I'm on Win 7 and play HoMM3 plenty and in all the time I've been playing it on this OS it's only crashed a few times. And thanks to autosaves it's not really a big deal.

Ahhhh the GOGWiki :D The thing is anyone can contribute to that and the person who added that information either didn't sign up for an account or didn't login and that was added over a year ago.

Anyways, Heroes 3 is known to crash on multicore processors and the fix is usually to set the game to run on only one core. Under GOG Support they have this:

Problem / question
Frequent crashes

Solution

If our game crashes frequently (especially when entering the town view), please try different compatibility modes, starting from Windows 95 (you can change these in the Properties of the game's shortcut, under the Compatibility tab).

If that doesn't help: after starting the game press Alt+Ctrl+Del, start Task Manager, go to Processes tab, right click Heroes3.exe and set affinity to single core.

For a permanent solution:
Open Notepad and copy this line:

start /affinity 1 Heroes3.exe

into the file, then save it as HOMM3.bat in the same folder where Heroes3.exe is located. This will create a script that starts the game with single core affinity for you. Double click the newly created file to start the game.