Thanks for the suggestions.It is CIBOX C1905 flat panel monitor and there is no specific driver for it other than Plug & Play Monitor.
As suggested I did uninstalled the plug & play montor via device manager and restarted the computer.No joy. Even the screen saver does not work. The only thing works is hibernation.
I logged on to the manufacturers site.No driver there too.
Next thing I will do to reinstalled the graphic driver. Will post back if it rectifies the problem.