I am trying to make some changes to the setup program that installs the game "Emperor: Battle for Dune". If you want to look at the EXE I am working on, you can download a copy of this setup program from the official Install Fix patch here: http://dune2k.com/Duniverse/Games/Emperor/Downloads/Patches (download the "Install Fix:" entry and it is Setup.exe).
For some reason, the developers decided to make the installer a fullscreen application and so I am trying to modify it to instead run in a window. It uses the DirectDraw API (not entirely sure what version but I think it is 7 or 8). Thus, I know that the function "SetCooperativeLevel" (https://docs.microsoft.com/en-us/windows/desktop/api/ddraw/nf-ddraw-idirectdraw7-setcooperativelevel) is used to initialize the DDraw application in fullscreen or windowed mode.
My problem is that I tried to disassemble the EXE using both IDA Pro 7.0 and OllyDbg 2.01 but neither of them have been able to find any calls to that function. Can anyone tell me if there is anything I can do to help one of these programs find this call? Alternatively, is it possible for a DDraw program to go into fullscreen mode without the SetCooperativeLevel function?
Edit: I attempted to use Defragger's suggestion below. Unfortunately, it didn't work. I modified the code he pointed out as per below to simply change the dimensions to 800x600 but it did not change anything. The window is still in fullscreen and doesn't appear different at all:
.text:004619BF mov esi, ds:GetSystemMetrics .text:004619C5 push 258h ; yBottom .text:004619CA push 320h ; xRight .text:004619CF push 0 ; yTop .text:004619D1 push 0 ; xLeft .text:004619D3 push offset Rect ; lprc .text:004619D8 call ds:SetRect
I found that I could only modify the "yBottom" and "xRight" parameters safely. If I modified "yTop" or "xLeft", the program crashed.