When i first start my laptop, it hangs for about 3-9 minutes. It is not complete hang , we are able to move mouse and even open some folders but unable to open any files, Even whole taskbar is hanged nothing happens. So pls guide me in solving this problem.

Is this a new problem? Were things working OK previously? Any new hardware or software?

If this is a new problem try a System Restore to a point prior to the problem:

start > All Programs > Accessories > System Tools > System Restore