hi
is it just in first moment(s) when u play bf2 or for all of the period of time that u playing ?
did u try to change game setting to lower resolution and gpu stuff ?
if u try this and it work , this means Ur gpu probably have some issues
however u should also check how much capacity of RAM , CPU , DISK is using when u are playing in task manager ( with Alt + F4 )
it can also possible because of viruses , or bad install .
note : in general u can test Ur PC hardware with software like : BurnInTest
i used it for my self