il y´a une explication mais elle est pas clair....y´a des incoherences dans ce que j´ai vus.....
voila a peut pres pour ce debarraser du logo 
A)Little tricky, you have to edit the lua file. Here´s how to do it:
1)Go to the supreme commander demo folder in the programs area on your HDD.
and go into the "gamedata" folder.
2) Open but DO NOT EXTRACT the lua.scd file using WinRAR (google it iif you don´t have it).
3) In the lua, navigate to lua\modules\ui\game and find the gamemain.lua file.
4) Open this file with Notepad and remove this line of code (it´s almost halfway down the page):
local overlay = Bitmap(GetFrame(0), UIUtil.UIFile(´/marketing/demo_overlay.dds´))
overlay.Depth:Set(GetFrame(0):GetTopmostDepth() + 1)
overlay:DisableHitTest()
LayoutHelpers.AtHorizontalCenterIn(overlay, mapGroup)
overlay.Top:Set(function() return mapGroup.Top() + 5 end
mais voila rien que ça ce n´est facile a faire 