can't change brightness in vista when in battery

i'm in battery and the screen gets automatically very dimm, and i try changing the brightness with the Fn+up/down keys but nothing happens apart of the animation of a sun with glasses wich appears if you have installed dell quickset.

i tried changing it in mobility center and power management in control panel, but nothing happens to...

In Xp (i have dual boot) everything works fine as expected in there..

what to do??

 

Did you install Vista or is it origional to the laptop. Did it ever work?

 

i reinstalled it from the disc that came with the notebook... then used the drivers available from dell's website.. but this was some time ago

i don't remember if it ever worked... i would say yes tough.

Everything works fine with AC power..


i don't know.. i'm gonna try reinstalling the video drivers.. and if i can the monitor drivers..

 

Did you try rebooting the laptop?

 

yeah it has been happening for weeks :hmmm

 

Try reinstalling dell quickset.

 

I noticed if I am on battery, then hibernate, then plug in, and wake up from hibernate, I have lost screen brightness control. Vice-versa as well. I usually have to reboot either way.

Hope that helps,
Snes

 

finally it fixed with reinstalling intel graphic drivers (got the lastest ones), (and maybe monitor? dont know if the were reinstalled)

thanks guys
QATC