Windows 7 - Fn+brightness control isn't working in DELL inspiron N505

greetings!
I've just got new dell INSPIRON N5050 but I can't set its brightness from Fn key.
is it a hardware issue or software?
sometimes it works and sometimes not.
i have Windows 7 Ultimate x64.

since you just got it, better off to take it back to the shop and get some servicing.

Assuming that your computer is new & under warranty -
I would strongly suggest that you should seek advice asap.

Appears to be a bit of both. Maybe a corrupt or missing hardware driver (software) that is keeping the hardware from functioning properly.
Are there any yellow, red or disabled symbols showing in Device Manager (show hidden devices)?

once i took it to shop, but it was working fine there was no bug. it sometimes works fine and sometimes not, and when it not, i just close it and open it in a second, it works fine. i have installed matlab2011 and many other big software, now it will be big loss to handover it to shop.

no dear, all drivers are properly installed.

Have you updated all the relevant drivers?


Please provide us with your Event Viewer administrative logs by following these steps:
{Instructions courtesy of writhziden}

Click Start Menu
Type eventvwr into Search programs and files (do not hit enter)
Right click eventvwr.exe and click Run as administrator
Expand Custom Views
Click Administrative Events
Right click Administrative Events
Save all Events in Custom View As...
Save them in a folder where you will remember which folder and save as Errors.evtx
Go to where you saved Errors.evtx
Right click Errors.evtx -> send to -> compressed (zipped) folder
Upload the .zip file here.

and f5 alone works fine, also all other fn+funcion keys work fine,
only sometimes, brightness control doesn't work.
should i reinstall window?
and if problem still remains then i'll took it to shop.

sorry for english mistakes.

yes, i did it,

no zigzag3143, i didn't updated any drivers, when i bought it, they installed everything.