SotC no longer working after reinstalling Windows 7

[gamebounty]

Shadow of the Colossus has always been a troublesome game to run because of frame rate issues, but I just recently installed an MSI Radeon R7 370 2GB graphics card and the game immediately started running smoothly. The next day I reinstalled windows 7, and ever since the game has gone back to its boggy ways and I can't figure out why that is. I've tried various settings, like GSDX SSe4 with DirectX 11 which should be ideal, but it still isn't working. Does anybody have any ideas why the game would suddenly stop working correctly after reinstalling windows?

Here are my specs

    Windows 7 Home Premium 64-bit SP1

    Intel Core i5 650 @ 3.20GHz    31 °C

    12.0GB Dual-Channel DDR3 @ 668MHz (9-9-9-24)

    2048MB ATI AMD Radeon R7 370 Series (MSI)

Any help will be greatly appreciated.