Unfortunately I changed the Display settings and restarted the system. After restarting the Display is in crashed i.e, it is rotated in Anti clockwise direction....
How to clear it?

It is very simple. Follow the below steps to set right it ok i a min...

1. Right click an empty area of your desktop.
2. Select Properties.
3. Click the Settings tab.
4. Select the Advanced button.
5. Click the Graphics card tab.
6. Select the Graphics Properties button.
7. Click the Rotation tab.
8. Uncheck the Enable Rotation checkbox.
9. Select Apply and exit all windows.