Can't play KS full screen anymore. Lost all old data

[Signs]

I have Windows 7 and had put quite a few hours in KS. Today when I tried to start it up, it kept minimizing from the full screen. The game wouldn't stay up for more than a second and a half at most before minimizing again. I uninstalled and reinstalled it to no avail. It wasn't fixed until I uninstalled it and deleted my save data and settings. I can play the game in windowed mode, but if I put it in full screen. It minimizes itself, and I have to uninstall it and remove my saved data. Does anyone know what I could do to fix this?