I know server 2003 comes with several desktop features disabled or crippled, so i could expect not being able to change my laptop brightness with the fn keys, but it doesn't work in xp x64 also! both 2003 and xp 64bits share the same kernel so I suppose this problem is some bizarre compatibility problem or bug, the key works out-of-box with windows xp 32 bits, vista, 2008, 7, 2008R2, and linux (ubuntu, fedora, opensuse), no need to install drivers! and so there is no proprietary drivers to install in my laptop (it is an old and custom built-in (no brand) with u50sa motherboard and sis chipset, ati mobility radeon 2400.) So i ask for help if anyone have any idea of how could I increase/decrease my laptop brightness with or without the special key, in server 2003, I made some research and it seem no software can't control the back-light of a laptop. out of luck?

You may be able to change brightness in the BIOS configuration. This may be worth a try also http://www.ehow.com/how_5057563_adjust-screen-brightness-windows-xp.html

software to control monitor doesn't increase or decrease the backlight to save energy, at least not the CCC or any other that I have tested, Its a exclusive feature of the fn keys (that NOT work on 2003 server... thanks

If it does not work in the server OS I am not surprised that it does not work in XP x64. XP x64 is based on the Server 2003 code base, not the XP client OS code. Bill