Overview
Running Unreal Tournament 2004 on Windows 10
Step 1
Run the game so that it will create the needed UT2004.ini file. The game will crash with the following error:
LockRect failed: D3DERR_DEVICELOST
History: UD3DRenderDevice::ReadPixels <- UD3DRenderDevice::Present <- UGameEngine::Draw <- UWindowsViewport::Repaint <- UWindowsClient::Tick <- ClientTick <- UGameEngine::Tick <- Level Untitled <- UpdateWorld <- MainLoop <- FMallocWindows::Free <- FMallocWindows::Realloc <- 10910191 0 FArray <- FArray::Realloc <- 0*2 <- FMallocWindows::Free
If you get a message saying, please enable direct 3D set the UT2004.exe to Windows XP service pack 2 compatibility mode. You can find the UT2004.exe file in SteamSteamAppscommonUnreal Tournament 2004System. If you do not receive that message you can skip setting compatibility mode.
Step 2
Edit the UT2004.ini file found in the same folder as the UT2004.exe file by replacing the ReduceMouseLag=True entry with ReduceMouseLag=False and save. You can find the UT2004.ini file in SteamSteamAppscommonUnreal Tournament 2004System. The ReduceMouseLag entry is listed under the [D3DDrv.D3DRenderDevice] section about half way down the page.
Step 3
Enjoy The Game.