Y550 fn brightness error after updating bios

[roterrion]

lenovo y550 4186 core 2 duo p8700 2.53ghz, since august 2009 i guess. vista 32bit home premium sp2. nvidia geforce gt130m up to date.

i just updated my bios to v2.08 (from the web) yesterday, after that i try to reduce my lcd brightness by fn+ down arrow, but the screen become brighter, and i pressed that again, the screen become dim, again, brighter (as bright as the first), and so on. so now i just can adjust my lcd brightness to dim or bright (just like 2 brightness option only).

similar to this video: http://t.co/GyIvPUV

i tried to search about this case, and the solution was to uninstall alive idea desktop completely, but i dont have that application since i bought this laptop.  i've tried to change brightness before entering any os and the result is the same.

so i consider it as bios update problem. any kind of help will be appreciated.

thanks

[yigit]

try to re-install power management and/or graphic card drivers.

[roterrion]

i did reinstalling power management many times, no luck. i have another windows7 64bit with the latest power management and the latest nvidia driver, same problem still occur.

[yigit]

press f8 to load "last known good configuration" when you see lenovo logo at start-up. if it doesn't work, can you perform clean windows installation?