GTS250玩GRID當機

昨天灌了GRID，遊戲顯示設定完成後，做儲存退出選單的動作後，就當機了。
連Ctrl+Alt+Delete都無法關閉遊戲，最後只好強制重新開機。
在遊戲中，畫面正常，動作順暢，但是拐了兩三個彎，又當機了。
後來試著將190.38版本的驅動改成舊的185.XX (忘了版本編號)。
結果看起來恢復正常了，不過玩個兩三趟，又當機了....
過程中有跑出兩次藍畫面。　

畫面資訊如下：

A problem has been detected and windows has been shut down to prevent damage to your computer.

The problem seems to be caused by the following file: nv4_disp

If this is the first time you've seen this stop error screen,
restart your computer. If this screen appears again, follow these steps:

亂碼
亂碼
亂碼

*** STOP: 0x000000EA (0x8969D020,0x89FA0320,0xB9125CBC,0x00000001)
nv4_disp

請問我應該怎麼處理？