My Screen Is Way Too Dark When Booting To PCLinuxOS.
What Can I Do?

So your screen is normally bright, but for whatever reason when you boot up to PCLinuxOS the brightness level is very low?

Try this:

1) Install xbacklight via Synaptic.
2) Open terminal and su to root.
3) List the contents of the folder /sys/class/backlight with this command:
         ls --full /sys/class/backlight
4) You should get a few hits:

[root@wishmacer backlight]# ls –full /sys/class/backlight
total 0
lrwxrwxrwx 1 root root 0 2012-11-04 02:10:05.023004946 +0000 acer-wmi ->
../../devices/platform/acer-wmi/backlight/acer-wmi/
lrwxrwxrwx 1 root root 0 2012-11-04 02:09:09.784000471 +0000 intel_backlight ->
../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/
[root@wishmacer backlight]#

5) Now, you need to find the correct command to use. We are going to push the variable into the correct folder. The variable and the folder will be different on all machines, but I think it's safe to assume the variable values go from 1 to 15.

6) So, knowing that, let's try the intel_backlight folder first:

echo -n 15 > /sys/class/backlight/intel_backlight/brightness

This, however, didn't go so well.

[root@wishmacer backlight]# echo -n 15 >
/sys/class/backlight/intel_backlight/brightness
bash: echo: write error: Invalid argument
[root@wishmacer backlight]#

7) So let's try the acer-wmi folder:

echo -n 15 > /sys/class/backlight/acer-wmi/brightness

BINGO! The screen became bright.

8) Now that you know what folder/file to modify, try changing the variable from 15 to a different value and see if you get better results with other numbers. See if you can go to 16 or 14, for example.
9) When your command is ready, open your favorite text editor as root and modify the /etc/rc.local file by adding the command as a last line.
10) Save the file and reboot.