Two questions:

[Kay]

...the second about save files in HF.

So:

1) How exactly do I play Hellfire over Internet? I use the program called Hamachi (it creates a virtual LAN network), and everything (chatting, creating games) seems to work except one thing: neither I nor the other player can't see the created games.
There must be people here who have some experience of playing MP Hellfire, can you help, please?
I have IPX installed. I also disabled the Norton FW I'm using, but that didn't help. I couldn't even ping the other opponent using Hamachi (though, as I said, we could chat).
And I have tried Kali and simply didn't like it, so it wouldn't be a good advice:)

2) Where do I find the save files for Hellfire mods like V & K or The Dark? I mean the multiplayer save files, of course.
I have enabled "Show hidden files" and "Show hidden system files", but it didn't help - still no findable files with "hf" in their names. And all .drv files don't seem to have any relations to Hellfire.

Well, I hope someone can help me:)

[Kay]

Well, one problem solved, thank you:)

[LennyLen]

I take it Hamachi works fine for you playing vanilla Diablo games?

[Kay]

I take it Hamachi works fine for you playing vanilla Diablo games?

I don't even know what you meant by "vanilla Diablo"...

[Phredreeke]

He means Diablo without Hellfire or any mods.

[Thenryb]

As to your first question, I have never seen anything but Kali which worked reasonably well but I guess you have already ruled that out. I have played Hellfire on Kali with people from all over the world. There are occasional lag problems and playing in a game with more than three players will almost always cause a crash, so it is not perfect but remains the best option available.

[LennyLen]

As to your first question, I have never seen anything but Kali which worked reasonably well but I guess you have already ruled that out.

Hamachi works well. At least for Diablo - I haven't tried it with Hellfire. It's arguably a lot simpler to use then Kali as well (not that Kali is difficult). Best of all it's entirely free.

[Kay]

Classic Diablo doesn't work either:/

[splatz]

I've spent some time getting Hellfire to work with Hamachi, and wrote a setup guide. You can check out the thread here

One tip: Make sure all parties are using the same version of Hamachi (preferrably the latest version).