When your computer is plugged in to a electrictal outlet the screen is brighter then when running on battery power. That is unless you are on my computer. A few months ago I noticed that when I was using the computer on battery power the screen became brighter then when plugged in to the wall plug. I bought a new power cord (with transformer) thinking there was a short or something. This did not help. Has anyone heard of this and know how to correct? I would appreciate any help with this problem before I go blind.

Thank you Toni Lucas

What make/model?

Possibly some changed power settings which can be accessed (in XP at least) by right-clicking a blank area on the desktop and clicking Properties. Then you go into Screensaver->Power.