Well, I personally think you should update your antivirus software because of the recent patch. AVG has now placed the new patch updates on its Whitelist meaning that it won't block it anymore, if you have AVG update it. If you've removed textures or still use hacks (which i highly doubt) then stop using the hacks or replace the textures. Alternatively (which i very highly doubt), is that you've been ip banned so just reset ur modem or use an ipchanger. However, when i experienced this problem, i just re-installed combat arms and it worked!!!! If your really desperate and nothing works, just reformat ur pc and reinstall xD