Yeah, that is what I thought, but like I've described above dedi refused to start without sound card drivers and that sound card enabled. So, this leads me to think that it needs also a SM 3.0 GFX card, but this is purely a guess - it shoudn't need it, it's a dedicated after all.
I used to host the server on my machine (i7, 8 GB RAM, HD5830) and the overall performance was good, and the RAM usage wasn't that high (around 800 MB at max at that time).
The current system is just bare XP that I optimized already, disabled unneccesary services etc., take up something like 70 MB from RAM, I take the explorer gui advice, thanks! But still I ain't got an idea why the server is refusing to start there, just closing down without any message on the checkbox thingy.