Web or Browser game start lagging on chrome

Hello,


This is Asad here. I play a web game on chrome . There is no need to download it. You just have to open it on chrome(www.rivercombat.com) then login into your account and start playing it.
A few days ago, I buy an old used laptop with 2/gb ram Intel Centrino 2.00...in first few day everything goes fine but now it lag very badly. I just buy that laptop to play that game. i have only 2 program on it. 1 chrome and other is dev c++. Still lagging it try to switch network to but still same ...internet connection is not the problem. I install new window but nothing change....Please help..