Heroes of Might and Magic 5 ==patched 1.06==

[Browser]

I know it's an old post but it's high in search results and I had the same problem. For me it was the installer screwing up on 64bit systems (Windows 7 x64 for me) while on the Windows 7 x32 it worked fine. So installing the game and the updates on either a 32bit system or x32 virtual machine then copying the files to the 64bit system solved the problem for me and may help others who find this post.