Setup:
STEAM USERS:
Go to your Steam Call of Duty 2 install directory.
Rename CoD2MP_s.exe to _CoD2MP_s.exe
Download this file.
Extract it to your CoD2 directory.
Launch game via Steam.
NON-STEAM USERS:
Download this file.
Extract it to your CoD2 directory.
Launch game via CoD2MP_w.exe
I have only tested this on Windows 10. It may work for Windows Vista and Windows 7. Quote from author;
It's very simple for Windows 10. I was really wondering but it's enough to create a form application and change the parent of the game. Then you only have to handle the resize functions for great flexibility.
The fix is similiar for older Windows versions. But before we can do that we have to change 2 bytes in 'gfx_d3d_mp_x86_s.dll' to force windowed mode.
Project source: https://github.com/Si13n7/CoD2MPWindowed
Big thanks to Si13n7.