Boot freeze (Gray Screen)

I cannot boot to a Windows 7 OS. Itt freezes on a gray screen I'm not sure what caused this. All of a sudden when trying to boot into windows on my iMac I can't get passed the grey screen. If I use the Option key to select the boot drive, it freezes the second I select the Windows partition.

I use iMac 2007 model with OS X Lion 10.7.4
Boot Camp is on 4.0.3

I can go on Windows Setup. When it finished on the setup I got into the Windows itself. I installed bootcamp that it was downloaded and install it. I did the latest update on windows update. After i reboot it freeze.

It was always like that, i reinstalled Windows, deleted the partion with boot camp. installed again. It's always like that after the 3rd boot