Have you tried re-installing your graphics driver?

There are some files in "my documents" that might not be deleted when you uninstall the game. It includes the saves, but also a few other folders. Maybe your config info are in one of those? Try copying your saves, then destroy the Conquisador folder in "my documents".

Try deleting your config file and then starting the game.

Okay, I've tried everything I could think of and all you guys recommended, thanks for that. But, to no avail.

Meanwhile though I found the problem, not the cause, mind you.

It seems like my GFX card got physically damaged exactly that moment when I tried switching the resolution.

At one point I tried starting another game and, lo and behold, same effect, black screen, only reset available. Some more testing, surprisingly some games work, some do not, and I didn't find the connection yet. May be its DirectX vs OpenGL, may be its the starting resolution, I got no idea as of yet. Anyway, the confirmation of definitely being a hardware problem finally was in changing that GFX card to another machine. Checking on that other computer showed the same results with the same games. So, that makes it a case for the bin.

And it leaves one dark question: what happened that moment I tried to change the resolution?

I guess I am familiar enough with all that matter to realize its NOT been the cause, of course even less, the fault of "Conquistador" to damage the hardware. And since obviously to this moment noone else encountered a similar experience, it simply was the proverbial bad luck that hit me, rather my GFX card. Though I never heard about this kind of hardware failing partially, as in works fine in WIN and some games, does not work with some other games. This seems really, really strange to me. Anyway, got a spare card dusted and installed now and everything works fine now.

Thx for the help,
take care
Kid