BSOD and problems while playing games.

Hey there i am new to your community.
Let me introduce you my computer specs:
Intel Core 2 Quad Q6600 @2.40GHz
Ram 4gb
windows 7 x64
Nvidia GTS250 * that's all i know about my computer ^^

So i got some BSOD while playing games and especially dota2, lol etc. Also before bsod my games are flashing, freezing, black screen and pops up a message saying: Display driver stopped responding and has recovered

Please help me i already have tried changing many drivers but problem didn't solved.
Here is BSOD report

Υπογραφή προβλήματος:
  Όνομα συμβάντος προβλήματος:    BlueScreen
  Έκδοση λειτουργικού συστήματος:    6.1.7601.
  Αναγνωριστικό τοπικών ρυθμίσεων:    1032

Πρόσθετες πληροφορίες για το πρόβλημα:
  BCCode:    116
 BCP1:    FFFFFA80061FA4E0
  BCP2:    FFFFF8800F17F354
  BCP3:    0000000000000000
  BCP4:    0000000000000002
  OS Version:    6_1_7601
  Service Pack:    1_0
  Product:    256_1
and the minidump file! * download - 2shared

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