Why doesnt gears of war work on my computer?

I installed it, everything seemed to go great, but now when i try to play it brings up a window that has gears of war and asks if i want to let microsoft collect data to make the game run better/smoother, i click ok and then play, then i get a message that says C:\Program Files (x86)\Microsoft Games\Gears of War\Binaries\wargame-g4wlive.exe: You cannot run the game with modified executable code. Please reinstall the game. Will this even do me any good to reinstall?? I have windows 7, my processor is Intel Duo Core 2.2 Ghz, 500 GB hard drive, 4 GB Ram, and I have an Intel GMA 4500M(crappy i know, but should work since its an older game) thanks guys for looking