Technical issues with Heroes III.

Svarog, unfortunately for all of us, there is no 100% reliable protection and no perfect software, including antivirus programs! :( Even people using KIS manage to "catch" all sorts of malware. You also need to use your head and not "fall for" various "scams," not click on "very interesting" links sent by strangers (and sometimes even acquaintances), etc.! And it's useful to periodically check your computer with a "fresh" version of DrWeb CureIt, regardless of how "cool" your antivirus is. And a lot also depends on the proper configuration of the antivirus. In addition, it is desirable to use a firewall (if it is not included in the antivirus package).
I have been using Avast for many years. I can confidently say: it is a quality product.