Seems the screen will not go as bright as it should for Windows 8.1, it does during startup, then dims down.

I have upgraded Windows 8 to 8.1 and just about everything seems to work. I updated to Bootcamp 5 after the install when I was getting warnings of compatibility. After the installation the brightness of the screen seems to be full, then when I login with my account it dims down to about what seems 50% and cannot get it any higher. The brightness in windows shows it is all the way up. What gives?