1. Check VGA driver, ensure that VGA driver installed correctly. Right click on Desktop screen ( on your laptop ) and left click Properties.
2. Click Setting and followed by Advanced,
3. Left click Adapter, You should see detail specification of VGA device here, but if just Unavailable there this mean that VGA driver not installed correctly.
4. If VGA driver not installed correctly as step 3, please check what bit your OS have just installed. For 32 bit you should install VGA driver for 32 bit OS, and if 64 bit you should install VGA driver for 64 bit.
Visit instant-link to get VGA driver for free and instantly.
I hope this post will help you to reduce or increase screen brightness of laptop, otherwise please write on comment area ang we will give you some advice to fix it.