After working in Windows 7 for about three months, it went strange. I had restarted my system manually since it hang and from the next run, the screen became smaller. Thought in the resolution, it showed my correct resolution 1600x900 but there are resolutions unsupported by my monitor also. The screen only displays in the middle half.
I had searched in the display properties and checked to display only supported resolutions. Still the same.
How can I fix it?