I cannot get any of the high res mods to work and the voodoo2 graphic utility doesn't work either. I have the grayface mod installed but all I get is mouse looks thats it. Nvidia Control panel doesn't affect anything graphically with M&M 6 at all is it because it is too old?
There really isn't a huge difference with the HD Textures Mod. This post does go over how to install it though: https://www.gog.com/forum/might_and_magic_series/how_to_apply_greyfaces_hd_textures_mm6/post3
As MM6 uses a software not hardware based engine, you won't get many improvements from playing with your GPU settings. You CAN use a wrapper like dgVoodoo2 if SupportTrueColor is disabled (SupportTrueColor=0) in the mm6.ini (Not necessarily better). Or if you have MM8, you can use the merge patch and run MM8 in hardware mode, but that changes the vanilla MM6 experience significantly and there's still some issues with it.
Additionally, If you do decide to use dgvoodoo2 make sure you have the files from the zips "MS\x86" folder in your root MM6 directory.
Really, my suggestion would be to install the HD textures IF it interests you and just play the game normally. I personally like using mouselook and re-encoding the music mp3s to wav and then setting "MusicLoopsCount=0" so that you get continuous music as well. (The re-encoding to .wav may not be necessary depending on your system)
Thank you the watermark shows up when the game starts up so I know its working but I get 2 side by side green screens I don't think MM6 likes it. The HD mod loads up at the start and takes a while at the second start of M&M 6 when starting up like it should but I don't see a difference.