Far cry 3 lagging [help]

So i Installed Far Cry 3 and it was working fine till 3 weeks, sudddenly its lagging bad,i meet recommended system requirement too and i have optimized pc with advanced system care 6 and advanced system optimizer but still lagging bad i dont know why can u please suggest me?
I Have
Display Adapters:
Amd Radeon HD 7400M Series
Intel(R) HD Graphics 3000
Processor:
Intel Core i5-2410M CPU @2.30GHz

 

Is anything else lagging?

Are you monitoring the temperature of your GPU and other components? Easy way to do that is to download this, check your temps and make a note of them, then start the game. Play for 20 minutes, then shut down the game and check temps again.

And when was the last time you cleaned out your video card to get all the dust out of the fan?

Also, try and remember if you made any major changes to the computer just before the problem started. Even if it seems completely irrelevant, it could still be important.

 

ya i see my Mother board and Cpu Temp is high average 90-95C and hard drive is 43C and i have cleaned my laptop fan two days ago ago

 

That's not high average, that's highly dangerous! :eek Water boils at 100C, keeping your CPU just below that is NOT good for it!

If your motherboard is at that temp as well, that definitely explains your lagging problems. More cooling, and better, and quickly, and your components may actually survive for the long haul.