Any other information? Are you trying to use hacks at the same time or no? I have had every problem under the sun with Combat Arms and managed to fix my problems, some more information would help. Computer specs as well.
YO DUDE test if you can play WITHOUT hacks, and WITH hacks, and WITH and WITHOUT mods, and if you try reinstalling it, and it doesn't work... Then search for an IP changer, and how to change a MAC address for your computer's CURRENT OS kk? That SHOULD help you because no MATTER what I did, when I reinstalled combat arms, changed my IP NUMEROUS TIMES, and removed all hacks, and mods, this helped me ALOT xD Also if you have a mod and wanna keep it running, change your MAC and IP EVERY time you get disconnected from the server ok?