You might make medium high, but most likely would be medium settings. The 650 isn't a terribly great card because it only has half the memory pipe of the 670 so it has a really bad bottleneck. even though it has more ram and processor than a 550 GTX, the 550 will outperform it because it doesn't have that bottleneck in almost all cases except for a few directX 11 specific rendering areas. That power supply is really low for a GTX card too. The 650 GTX will technically operate on a 430 watt PSU, but that leaves you zero margin for any upgradability at all. You put another hard drive in that system and you will start underwatting. You put enough extra fans in that system and it will start underwatting. Etc. Corsair makes pretty good power supplies so you should get the advertised 430 watts, but you are running awfully close to the edge with that. Ram and the rest of the specifications are ok for gaming, though a dual core processor is at the lowest end of the spectrum. That shouldn't affect gaming much though, just multitasking.
Also get rid of windows 8 as soon as possible and go with Windows 7 or wait for windows 9.