Cannot change the display brightness in Windows Mobility Center - Notebooks
For affected ThinkPad Systems, the display brightness slide bar in the Mobility Center is grayed out. For the affected 3000 Family notebooks, the display brightness slide bar in the Windows Mobility Center cannot actually change the brightness.
Any of the following systems running Microsoft Windows Vista:
3000 N100, V100, C200
ThinkPad R50, R50P, R50e, R51, R51e, R52
ThinkPad T41, T41p, T42, T42p, T43, T43p
ThinkPad X31, X32, X40, X41, X41 Tablet
ThinkPad Z60m, Z60t
You can change the display brightness by pressing Fn+F10 and Fn+F11.