Disclaimer - All at your own risk. Backup first.
What you almost certainly have is Control Centre but not the Hotkey Package which includes Control Centre. Without the package the Keyboard backlight control simply will not appear in your control centre menu.
I am not sure if you have "upgraded" or if you have fresh installed.
A good starting point would to do a full back/image up of W10. Then uninstall your existing Control Centre and then run Ccleaner. Then proceed
To get the Keyboard Backlight working you have to have the following two items.
1. Vaio Hot keys (which also installs Control Centre).
2. Shared Library.
Lets do Hot Keys first. If you look at the support page for your model you will see that the HotKeys package is missing from software downloads. That is the bad news. The good news is that Hotkeys has been on version 1.0 forever and is still on version 1.0. So you need to find it somewhere else. I found it on the USA support site. Here:
https://esupport.sony.com/US/p/swu-download.pl?mdl=SVF1421DCXW&upd_id=8632&os_group_id=24https://esu...
This is the exact version that I used and it works in Windows 10. Install it (not in compatibility mode. Just install it) Be patient. Eventually it will say installed so reboot. When you reboot just wait.... it will take you through the same install procedure again!
Eventually it will say install complete. And may ask you to reboot for a second time!! After a few moments it may warn you that you are changing your power/hibernate setting. And are you sure. Say no to that. If you say yes just go into your power plan later and restore defaults.
Now look at your Windows 10 app list. You now have Control Centre. The keyboard backlight control is still missing. That is why you need Shared Library.
The good news is that Sony Shared Library does appear in the software for downloads for your Vaio. Here.
http://www.sony.co.uk/support/en/content/cnt-dwnl/SVF15A1M2E/list
Halfway down the page. Under windows 8. Just install it as normal. (Not in compatibility mode).
Now go back to your Windows 10 app list and open your new Control Centre. You should now have your Keyboard Backlight Controls. And a control to turn your trackpad on and off.
But wait.......Why would you risk installing Hotkeys for a different Vaio model just because somebody on the Internet says that it is the same version 1.0 software across a large model range? And why would you install a Windows 8 Sony Shared Library on your W10 installation.
Well.......possibly because you don't have much choice if you don't want your Keyboard Backlight glowing for the rest of eternity.
I am sorry to say this but Sony have abandoned you.
You asked for support more than a week ago.
Where is the support??
So you have to adapt. The above procedure is exactly how I got a fully working W10 Control Centre on my own supported but not supported Vaio Laptop. And my Laptop is also an SVF model. But this is why you should and must do a full W10 image/backup before proceeding.
One more thing. There is an update for Control Centre (for W10! Wow!) which is just cosmetic I think. You don't have to have it. If you want it post back and I will search for it.
Let me know how you get on.
