Thank you for your patience and effort. Finally I remembered the installer asking me if I wanted to install the DX9c at some point. So, to be sure its the 'version' I need, I just uninstalled/re-installed the game and, there it pops up the install dx9c yes/no window. After installing it, I removed the file as suggested and lo and behold it works!!
Everything at max levels, it works like a charm. Very fluid, I have fps locked at 60. Works for me.
First impressions: all walls are the same lol. Ok, except for some decorations and the..er...loose rocks ofc
Just at the start, and can freely say that the game gives new..uh..meaning to the saying 'snail food'
No idea what i'm doing, just picked up the pre-defined party and am goofing around. Apparently discovered (by pure luck) some flame ball little spell. My mage fried some snails with it and it looks awesome.
Just what i needed. After all these years of playing Dungeon Master on/off, its a godsend gift.
Btw, my first DM was the Commodore Amiga one

On PC I am playing the 'Return to chaos' version, where I can freely redefine action keys, crank up the level of difficulty and the multiplicator of monsters spawned per pack. Works well, but got old too.
Cant wait to dive into the Grimrock Mountain.
Not feeling any motion sickness yet (was a problem that prevented me to play Half-Life 2 for example).
Ah the system: Core2 duo 6600(2.45GHz) , 2GB RAM and Geforce gtx 275 (an old rusty bucket).