If you recently installed patches or are running a digital reissue, the directory files might be mismatched with the primary launch executable.
Delete the configuration files inside (look for config.cfg and config_mp.cfg ).
In the same players\[profile]\ folder, open config.cfg again.
Because CoD 2 was built before high-refresh-rate gaming mice, it ties its frame rate directly to its input processing. If the renderer isn't perfectly synced, players experience "mouse acceleration" or "floaty aim."
In , add one of these at the end (after the quote):
For a desktop shortcut, the full target should resemble: "C:\Program Files (x86)\Steam\steamapps\common\Call of Duty 2\CoD2SP_s.exe" +set r_renderer "dx9"
The most common cause is a version mismatch between your game and the executable.
Alternatively, install (June 2010).