How to know that your Graphic Card it not work correctely

i had before many problems in my computer and i search all over internet without finding any solutions. this is a screenshots about these problems :

also java and flash player and the most of my programs crashed. and sometimes my computer give e a BLUE SCREEN OF DEATH error and restarted.

i try to change the operating system ( i try windows xp, vista, 7), i change my antivirus, update my drivers. but i still get the same errors messages. then i know the problem is not a software problem, its a hardware. but i don't know exactly which hardware is faulty.

these weird problems make me crazy until i found whats wrong in my computer ( just by luck)

one of my friends want to sell an external graphic card. because i have weak integrated graphic card i buy it from him. and the suprizse is when i plugged the new graphic card (it was Nvidia because my integrated graphic card is Nvidia also) all those problems gone and my computer work very well until i upgrade it.

so if you get like those crashes frequently  check your graphic card by testing another working one and see the result.

if you have any questions please leave a comment