Sudden shutdown with little blur near cursor @ Inspiron N5010

I have been using my INSPIRON N5010 from last 3 years.

I was facing frequent blue screen errors atleast twice in a day. When i saw the cause of blue screen in 'My Dell' application, it points to atikmdag.sys file. I neglected it for 2 weeks. Then it used to shut down suddenly after an hour usage and slowly it got reduced to 5minutes. Then i tried with uninstalling display driver and it used to run for 2hours and again sudden shutdown. sometimes, when i try to restart immediately, I face continous 8 beep sounds and have to restart it only after a day. 

Is this problem only with graphic driver or motherboard too??