Make Combat Arms windowed [without any downloadings]
It's is how you make CA run in windowed mode
Right-click on the Combat Arms desktop shortcut.
Click on the "Target" field.
Add "-w" without the quotes to the end of the command line. The new line reads "C:\Nexon\Combat Arms\Engine.exe" -w if done properly.
Click "Apply."
Double-click on the modified shortcut to run Combat Arms in "windowed mode."
and you're done
Credits for Ehow