Sony VAIO laptop upgrade to Windows 8.1 brightness problem SOLVED!!!

It seems you have the same problem as me (though I use VAIO S12X9E). If yes, then none of workarounds frs topic or fromom thi anywhere else work and brightess is inoperative and stuck on pretty low level.

Luckily after days of searching I found that there is a way to fix this - Fn+F5/6 still won't work, but other ways to adjust brightness are working, and finally max level is as bright as it was on Win7.

You have to edit registry key FeatureTestControl in:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class{4d36e968-e325-11ce-bfc1-08002be10318}\0001 (OR 0000)

Change its value to whatever it was on Win7 (the key can be found in the same place or in CurrentControlSet - you should check it to be sure, but you can also try mine value - then remember to write down your Win8 standard value so You can revert the change in case mine doesn't work for You).

In my case it was fb20 (hex) - that is for VAIO S12X9E with Intel i3 1st gen./Intel HD Graphics.

This fix with right value should work for any Intel HD Graphics.

Since there isn't a solution in this thread, I've gone ahead and opened a question on a clearer Q&A site, Super User.

You can find the question here:

http://superuser.com/questions/723641/cannot-change-brightness-on-sony-vaio-fit-15

Enjoy BobDeLoyd with Sony, Intel and Windows!!!!

I have now restarted my system and all of a sudden the brightness level can be changed up or down.

This Win 8.1 is so stupid that it does not understand Shutdown, it only understands restart. 

All along, I used to shut down my system for safety, today on a hunch, I thought why not try restart. And voila, all works fine now.

Give it a try.

And yes, Enjoyyyyyyyyyyyyyyyyyyyyy

KHS123

HA! Right after I read this from you I checked my brightness and it is not working anymore, darn! Unlike you mine is stuck on the highest setting. I guess Sony and Microsoft love making fools out of us :(

I also have a Dell Venue 8 running win8.1 and if you download these 3 updates you lose your WIFI... I spent many hours on this doing what they said to do and it was just a runaround, so I just uninstalled the 3 updates and hid them from Windows update... problem solved.

Seems like all I do lately is troubleshoot Microsoft's software.

Funny how life is. I was having problems with my brightness since I updated to Win8.1, I got tired of the brightness and decided today to do something about it. I tried to do all the Vaio updates, read through all these and really didn't find any that worked for my Vaio E Series SVE1413CCXW

AND THEN I noticed Windows Update had this waiting to be installed:

Intel Corporation - Graphics Adapter WDDM1.1, Graphics Adapter WDDM1.2, Graphics Adapter WDDM1.3 - Intel(R) HD Graphics 4000

Installation date: ‎3/‎2/‎2014 10:37 PM

Installation status: Succeeded

Update type: Optional

Intel Corporation Graphics Adapter WDDM1.1, Graphics Adapter WDDM1.2, Graphics Adapter WDDM1.3 software update released in January, 2014

Now my Brightness controls work just fine :)

Thanks BobDeLoyd for the input.

Like you, I also downloaded the update immediately on seeing your post, applied it and was happy for exactly a day.

That's right, only for a day! Because the very next day on 4th March to be precise, things were back to normal, I mean abnormal, Lolzzzzzz.

The brightness level has got stuck at the lowest level again. It does not move up at all.

Guess Win 8.1 has screwed up everything and neither Intel nor Sony is doing anything in the matter at all. Nor will they ever do anything about it, not even Microsoft for that matter.