Playing Heroes of Might and Magic V on Ubisoft servers.

Can you tell me what to do?

Practice more: D
If seriously – what is the problem?
There are 2 ways to play over a network:
- on Ubi.com
- through Hamachi
Everything about Ubi is described in the manual.
And for playing via Hamachi, read the corresponding topic... for example, here:
/topic/4742/
You just needed to look at the section; the topic was only 2 lines below the one where you posted