I seriously doubt your cpu might struggle to keep up with BF3 but it might run. I had a friend with P4 3.0ghz 2gb 9600GT that runs Battlefield Bad Company 2 on 1360 x 768 @ 30fps on low setting. But since BF3 is more demanding it might struggle. If you had a Core2Duo, say like my old PC Core2Duo 2.4ghz, 2gb ram, 9600GSO it can run BF3 at 1360 x 768 res @30-45fps on low to medium settings. A GTS450 will be enough. Try built a cheap AMD A6 with 4gb ram and a GT430, BF3 can run @30fps on low 1360 x 768
The answer is the same as your other near identical post, its not possible on a pentium 4. The answer is the same regardless but you should also post which Pentium 4 and if you have a PCIE x16 slot on the motherboard.
not gonna happen most p4 boards had pci and agp gfx slots not pci-e.
even if it was pci-e it would be pci-e 1 and that means all current cards would be incompatible.
to run bf3 on minimum you need a 2.4 dualcore or quad core and a gtx 250/hd 3750 and that will just get you 30 fps on minimum and will cost about 400 to make that build new... 150-300 second hand. to play multiplayer you need a quad core and a gtx 260/hd 4870 to enable 60 fps minimum.