Could I play BF4 with these specs



I think you are referring to your r7 240 (with 2gb it could be either way). Go to Catalyst control center on the Hardware section and check the specs of your gpu there. But you can play BF4 at medium settings. Again fps depends on the type of the card. About 30-50 fps with the ddr3 version, with maybe some dips below 30.
 

It's a Pre build system on pc world in the u!
The PC is the lenovo h50
 


It may be a pre-built but you need to have AMD Catalyst Control Center installed (it is the program that installs and controls your gpu driver), if not go ahead and install it.. If it as a pre-built I'm guessing is the ddr3 version of the gpu.