Performance slowdown on dell inspiron 1564 laptop

avil172

Estimable
Sep 14, 2014
13
0
4,560
i3, M330, 2.13 GHz dual core. 4GB,500GB,win7x64 home basic, AMD raedon mobility 5450 (laptop)
(sorry for my bad english; i am from india)
hello
my laptop runs some good graphics games at medium-high settings, but it only happens for the first time i open the laptop and run a game
after i close the game, and restart it after sometime, i experience heavy performance slowdown(even if i adjust the graphics settings and play with the lowest possible settings)

i checked the fan and its performing normally, air is going in and out like it should, fan is clean...laptop is not getting overheat either.
i use tune up utilities and my HDD space and registry etc stuff are all okay, what could be the issue?
 
things gone worse and its not even booting now... along with a lot of other problems.
now i am going to repair it for the last time so that i can sell it and buy a new laptop.
thanks.