Cannot adjust the brightness in Lenovo g560

I am having the Lenovo g560 which is very good to use and I am very happy with that. But there is only one thing that is annoying me and that is the brightness of the screen. Once I start my laptop subsequent to the hibernation then I am not able to control the brightness of it. Once this happens then I need to restart the system and then only I can start it again and control the brightness. This looks very strange but its true in my case. Please tell me that what should I do to avoid this issue. Please reply fast. Thank you.

If the display driver in tour computer is not functioning properly then also it may show the symptoms like this. So just to make it sure you can try by uninstalling and installing it over again. If that solves the problem then its fine and if that fails, then you can go for updating the driver to the latest version of it available on web. Updating the driver will be the better option as compared to reinstalling it.

Power Manager can also be one of the probable reasons for this. If that is supplying more or less power as it is expected by the system then it can do such thing. What you can do is just reinstall the Power Manager and this can help you. There are some of the similar cases on other sites where reinstalling the power manager solves the problem and I hope that this will do the same thing for you as well. Please post back if that helps you or not.

Other than the two things that are mentioned above, you can also try to update the BIOS to the latest one. I am not very sure that this will solve the problem. If it does not solve the issue then it is not going to harm your system in any way. So it will not be a bad idea to give it a try and see what it does for you. I hope you will be out of this soon as I know this is very frustrating problem.