Firstly, make sure that your computer meets the minimum system requirements to run Combat Arms:
- CPU: Pentium III with 1 GHz or better;
- RAM: 1 GB;
- OS: Windows Vista or better;
- Video Card: NVIDIA GeForce2 MX or better;
- Sound Card: Yes;
- Free Disk Space: 6 GB.
If the requirements are fulfilled, remove the game from your computer and install it again. After that, configure your security program and Windows Firewall to allow it to communicate. Also, right-click the task-bar, open Task Manager and close all unnecessary applications that use your Internet bandwidth.