At times, laptop users may have problems adjusting laptop screen brightness, where the system does not respond to the brightness changes. More specifically, the laptop screen brightness cannot be adjusted until the system is restarted or rebooted. Here are solutions that may work for some users.
hibernation
Prevent Vista Hibernation Wake-Up Problems
In Windows Vista, when using “Hibernate” mode, your system may wake up or resume unexpectedly. Solve the problem of your computer waking up itself with these steps, based on the most likely causes of this issue.