My all 3d games are now viewing in 640x280 screen resolution, it wasn't like that before. I'm using Intel(R) HD Graphics Family graphics card that came inbuilt in my Notebook PC, My games run fine but now all Full-Screen 3d games are viewing in 640x280 screen resolution. Everything is fine with my PC but the games are viewing like that.
It all happened when I downloaded a game made for windows 3.x- windows 95, it viewed in 640x280 screen, I executed it on my machine and it freezed for a moment and started lagging, I closed it and lo! My screen became small with 640x280 screen resolution, I corrected it using the resolutions menu and it came back to normal, but when I run my games, all of them viewed in 640x280 screen, it wasn't like that before I run that old game. My games are stuck in that resolution and I can't change the resolution from the games'-settings. I think there's a problem in my windows screen-resolution settings, I don't know how I can change these settings but will you please explain all the possible solutions. I've attached the images, before and after that problem.