a little problem with dim light in windows xp and 7

hi all, i have a little problem with my old laptop running windows xp, but i think may be also common on windows 7.

Ok, this is all:

when i use my laptop to navigate, read, write, etc.... i prefer to set dim light to 60 - 70%, just decreasing light by pressing Function key + F9; however, when i reboot windows, it reset light to 100% by it self and i have to decrease again it to 60 - 70%.
However, it is not a very problem but i am not able to understand and to change dim light on windows permanently.

 

Hi!

You should set the brightness by using:

Control Panel\Hardware and Sound\Power Options

settings - using your Func keys to set brightness will work, but they won't persist through a reboot. Settings in Control Panel will last through reboots, and you won't have to manually change them again everytime!

Hope this helps!

 

mochaultimateis spot on, but with my ASUS & win 7 I can use either method and the settings persist after reboots. Depending on your Brand and model I would check the manufacturer's site to see if there is a software update to fix this behavior.

 

When i use it with battery, luminance setting go at 70% but when i use with ac adapter it go by it self at 100%. If i uninstall video driver, i am able to change luminance and it remain at these settings. I think there is a problem with video driver that set luminance by it self but there is also a setting on windows xp (a register key, i think) that it is possible to change to regolate luminance. Windows change it every time laptop use battery instead ac adapter.
I would that its behaviour with battery should be the same with ac adapter.

 

@OP

You need to look into changing Window's power profiles to do exactly what you want it to do with respect to brightness settings.

 

thanks all but your suggestions do not work properly on my laptop; these settings change by brands. i have found these utility:

Desktop Lighter - Free software downloads and software reviews - CNET Download.com

|MG| Gamma Panel 1.0.0.20 Download

and they seem work on my computer, but i am not so satisfied.

 

I have solved; this info can make happy some of you:
there are two registry key, one called "ACBacklightLevel" and one called "DCBacklightLevel"; these are setted by windows that read the bios and put values on them about the backlight levels; e.g. in my case there are 7 levels of luminance. On "ACBacklightLevel" Windows puts max value, so it is "7"; in "DCBacklightLevel" puts a minor value, "4", to make screen readable at minor power consuming. If anyone does want to set different value, he have to change the number relative at the registry key, so for example: "ACBacklightLevel" to "4" make screen readable and save power (and, may be, eyes) also in AC mode without to remake every time the manual adjustment.