Tiberium wars 3 lag

[thegunners]

hi, i recently purchased command and conquer 3, i installed it to my system as usual, the game ran perfectly when playing missions and skirmish,but then i found out that when u add more than 4 players on skirmish it starts to lag like hell,so i looked at the required specification of the game but my system was above the required system sepcification so i was wondering if u guys/girls can help me out here to solve this problemo,

System specs:
CPU: Q9300 core2quad
GPU: HD4870 512mb
RAM: DDR3 4GB
Operating System: vista 64bit

 

[thegunners]

san some on plz reply i cant figure wot the fk is wrong with it!!!!!!!

 

[thegunners]

THANX FOR THE RPLY, i used the anti virus and i didn't find any viruses
i have also done everthing that you have told me to do and i stlll get the annoying lag, i thinks its the game and its not probably optimized for pc that well!!!!

 

[thegunners]

so has anyone had this lagging problem before and solved it eventually, if u have plz help tell me how as i reallly badly need to play this game!!!!

 

[thegunners]

so i believe that there is no one out there that can help me out?????