I noticed today my laptop’s brightness could not be adjusted any more, I wasn’t sure what was causing this as I disabled some services and startup programs to conserve cpu/ram. But in the end that didn’t seem to be the cause of this issue. I googled for a couple of minutes and quickly came to a thread on the Microsoft Social boards which had numerous posts by people who have the same problem.

– These people have a wide variety of laptop brands and types
– The symptoms are the same
– There seems to be no fix yet

The problem is as follows:

Whenever you have your laptop go to standby (Windows XP) or  Sleep (Windows Vista/7) brightness adjustments won’t actually change your screen’s brightness any more, even though the slider graphic appears. I have just tested with hibernation and it does not happen with this mode. This seems to be a Windows 7 problem as I’ve seen that people who are complaining about this all have 7.

The only “fix” at the moment is rebooting your laptop. Again a problem Microsoft should fix some time.