FPS drop to 0 in Radeon HD 7730

recently, i'd buy a Crysis 3 but it didn't run well in my PC so i feel like i just waste my money for the game that i didn't play..

and the NFS Rivals.. it didn't run smoothly too in some area (15fps) but it run in 35+ fps in high setting w/ HBAO.. so another money wasted..

and now, im planning to buy a Battlefield 4 and it's expansion packs but before that..  i downloaded it first via torrent just to

make sure if my pc can hadle it.

aaaaand.. my pc can run it in high settings /w HBAO no MSAA in 35 fps + !! im happy with that fps also in ultra sometime it drop to 25 depends

on the area where i am,

but... there's a problem. it suddenly drops the fps to 0 or 1 many times in a row its almost not playable.

i already tried the fixes found anywhere but none of them didn't help..

is the problem is my PC ?

this is my PC specs:

an ancient AMD Athlon II x2 250 3.0ghz (Overclocked to 3.5ghz)

4GB DDR3 Ram 1333

PowerColor Radeon HD 7730

500GB Western Digital HDD

Windows 7 64-bit

i'm using an AMD Catalyst 13.12 drivers

tell me if it's because its cracked or an Original Battlefield 4 game can give me best performance..

or if the cpu or ram is the problem just tell me, ill buy a new one before buying an original game..

don't say anything bad to me please.. i just don't want to waste my money again like what happens to me before..

Thanks and more power !