Games are unplayably lagging after two or three minutes of gameplay

PCGamerX

Commendable
Mar 29, 2016
17
0
1,510
Hey there, I have an issue on my brother's old computer.
When he plays a game and keeps playing for at least three minutes, game is lagging seriously!
Today he tried playing Need For Speed Most Wanted: A Criterion Game with medium to high settings at 1280x1024 Resolution.
As I expected, I saw the game cannot be played and starts to slow motioning and leaves player out of control after a smooth gameplay of three or two minutes.
I advised him and checked GPU Temps, it was 92°C temp and 92% load during playing Need For Speed Most Wanted: A Criterion Game!
I checked its temperatures using GPU-Z and Speccy, all are same and I think they reported correct temperature.
Then, I got his GPU out and removed fans, cleared dust, applied good thermal paste and reseated fans and attached and tested again as I thought this was a GPU Overheating........
Yes, it was overheated but now it isn't, it was still 92% load during gaming and now it's temperature reporting around 55°C ........So overheating resolved, but still same behavior....Lagging and leaves player out of control after three minutes.......

Game-Debate testing:
http://www.game-debate.com/games/index.php?g_id=3976&game=Need+For+Speed%3A+Most+Wanted+2&p_make=Intel&p_deriv=Core+2+Duo+E8400+3.0GHz&gc_make=Nvidia&gc_deriv=GeForce+9600+GT+512MB&ram=2&checkSubmit=#systemrequirements

His system specifications:

CPU: Intel® Core™2 Duo Processor E8400
GPU: Legend GeForce 9600GT 512MB 256 Bit
PSU: Generic 500W with one 6 Pin connector (May be crappy)
Motherboard: Gigabyte GA-G41M-Combo (Rev 2.0)
RAM: DDR2 667 (@333 MHz) 2GB RAM
HDD: Hitachi Deskstar 250GB
Case: Generic MIcro-ATX Casing with one Chassis fan
Intel stock CPU Cooler

Please tell me why this lagging happening.
Thanks in Advance.
 


Yes, I forgotten to say, I also did it.........
I applied thermal paste also between stock cooler and CPU Plate.
 


CPU Temperature keeps changing between 50° - 60°C during gaming ... After few minutes of gameplay, it still have same behavior and keeps between 50° - 65°C ....