I have a Lenovo P400 Touch. The brightness of the display could not be changed. I read on the internet that to correct this. Turn the power on when the LEONOV comes on the display press the bright + key and the display will get brighter. once it boots it will not adjust again until the power is turned off and on again. Hope this helps you.
Since installing Windows 10, I am unable to turn off or hibernate my laptop without having a dim screen upon restart. Once I revert to basic graphics, I get a bright screen BUT basic does not allow for a second screen. If I revert from the Intel HD Graphics 4000 to the basic, I go from dim screen to bright screen. If I re-install the Intel HD 4000 drivers while the computer is on, I keep the bright screen and can run a second screen. Once turned off, on every re-start, I must go through the same process - back to basic, re-install HD 400 drivers, re-start and then two bright functional screens again. It is time consuming and a major hassle. Any ideas? I need the second screen to operate. Using only the laptop in basic graphics mode is not an option.
I have done the same thing with the same results. However, after turning off my laptop and then restarting with the Intel HD 4000 graphics card, I get a dim screen again. So I roll back the drivers to Basic in order to get a bright screen again. Once bright, I re-install the Intel HD graphics 4000 drivers so I can run dual monitors (not possible if running the Basic graphics drivers). The time waste each day is tiring. Any ideas? Running dual screens is necessary for my work.
the solution ivandavid1 proposed worked for me. I have a Lenovo Ideapad Z400 and had tried just about everything to solve the brightness problem after installing windows 10. Is there news about the update for the intel graphics 4000 driver?
Installed win 10 on a win 7 pro upgrade from Vista home, 4 GB HP a6600f, dual core processor (I think I miscalled it an i3 in my profile). Seemed to work fine, but overnight, lost the Display in Device Manager (showed as unknown device... colors and screen size were screwed up). Tried to re-install driver for display in Dev Mgr... could not do it, so I rebooted and device driver from win 7 was OK, and everything looks good. I may have let it go to sleep. I will see if there are any other problems. some problems with network settings for lan systems, but I figured it out on the Dell system.
Ooops, I just let the a6600f system go to sleep, and the display problem re-appeared. Looks like I need to try a new graphics driver. I will post more info after testing a new driver.
Last edited by SierraJW; 23 Jul 2016 at 17:02.
IvanDavid1, you're a genius! My Lenovo P500's screen went dim three or four days after I upgraded to Windows 10 (July 28, 2016). I updated, installed and uninstalled drivers like others recommended, but none of them worked. I finally found IvanDavid1's solution today and it worked!!! Thank you, IvanDavid1.