Optimal screen resolution problem on eM350

Hello Everyone,
I had this netbook which I often use, eMachines eM350. During lunch break or free time, I will play games on my netbook.
Games like cooking dash, worms armagedon, DOTA, etc.
The problem is that, after I exit every game, a notification will always appear saying, "This not your Optimal screen Resolution for primary display device. Your optimal screen resolution is 1024X600 ".
How will I fix this problem.
Please help.
