LG R500 - Video Crash Issue

Hi guys, i've found this forum to be very useful for alot of issues, maybe you'll be able to help me out with my problem :

(Sorry if my english isn't perfect, i'm frenchie... =D )

I do play games like : Warcraft 3FT (dota) , Counter-Strike (old school 1.6), TFC, etc...

My problem : I got some huge "spike lag" in game, and it's not due to my connection (it does it even in offline mode). Wasn't able to figure out the problem, i decide to put net_graph 3 in the CS console to see if anything was going wrong.

I found a major problem : When it "spike lag", my choke goes like crazy to 50-60, then to 0.. It do lag whenever there's action, or not.. It's like a spike lag due to lack of memory or whatever.. i just don't get it!

Recently, my OS has found that problem (yay!) and has "provided" a solution, which is to download the lastest drivers. The main problem is that my drivers are updated perfectly.. and i still have lag issue.

There's the problem description as shown in my OS :
(Sorry my OS is french, but i'm sure you guys can figure what is that description)
--------------------------------------------------------------------------
Description
Un problème rencontré avec le matériel vidéo a provoqué un dysfonctionnement de Windows.

Signature du problème
Nom d’événement du problème : LiveKernelEvent
Version du système: 6.0.6001.2.1.0.768.3
Identificateur de paramètres régionaux: 3084

Fichiers qui aident à décrire le problème
WD-20080607-2150.dmp
sysdata.xml
Version.txt

Informations complémentaires sur le problème
BCCode: 117
BCP1: 84B2F388
BCP2: 8C80E350
BCP3: 00000000
BCP4: 00000000
OS Version: 6_0_6001
Service Pack: 1_0
Product: 768_1
--------------------------------------------------------------------------

Would i need to uninstall/install drivers to solve this issue?

Thank you for the further help, and if you guys need any clarifiation, just tell me =D

-careface

LG R500 - T7300 @ 2ghz core2duo - Nvidia 8600GS 256mo - 2go RAM