08-11-2015 11:15 AM
Thanks for the info. Yeah, I'll probably roll back to Win 8.1, take Lenovo off my mailing list and look to ASUS or Toshiba for my next computer.
I don't think that the situation is different with Asus and Toshiba. There are models also that are not advisable for Windows 10.
08-13-2015 07:21 PM
you may be right. i guess the bottom line is to never download a recently released version of Windows. wait a few years until it's proven itself stable and reliable. again, thanks for the reply.
08-19-2015 02:23 PM
To everyone in this forum having troubles. Yes the installation of the old driver is the fix. I had the problem even with Windows 8.1 and had to revert to the old driver before. This is the second time I had to do it with Windows 10 so far, so a total of 3 times. But the reason I think that happened is because the P400 is constantly updating and it must have reinstalled a newer driver. So I hope this helps everyone that is concerned.
REVERTING BACK TO WINDOWS 8.1 WILL PROBABLY NOT HELP BECAUSE THE PROBLEM EXISTED THEN TOO.
08-21-2015 09:39 AM
I rolled back to Windows 8.1
All of the problems that Windows 10 caused, including the dim screen, disappeared.
Dump Windows 10! Wait until MS and the manufacturers fix the problems.
09-10-2015 09:27 AM - edited 09-10-2015 09:28 AM
Hey I know some of you guys get notifications when something is posted to this board. Just wanted to let you know I found a fix for the dim screen problem. Download intel video driver 126.96.36.19932 for the p400 touch. Here's the download page. http://support.lenovo.com/us/en/downloads/ds031547 This worked for me hopefully it works for you guys too. It's an older version but it's more stable, also I've noticed Windows 10 is a bit more stable for the laptop even though it still doesn't get official support from Lenovo.
09-15-2015 11:43 PM
Also, Windows 10 likes to annoyingly update drivers without telling you, so you're problems may come back. If and when that happens, just go to the display driver settings and select the roll back option. This should prevent any future hiccups.
10-02-2015 04:31 AM
You can use the old Windows 8.1 driver, by selecting the "Allow Unsigned Drivers" option in the troubleshooting menu. To get to that menu, hold down the shift key while clicking Start > Power > Restart.
I manually installed the legacy drivers on my P400, and windows 10 works perfectly.
11-07-2015 10:32 PM
I found this solutuion and it worked for me.
Open Device Manager (Search for it or right-click Start). Confirm the UAC prompt, if necessary.
Select Display Adapters and right-click on Intel HD Graphics 4000, then select Update Driver > Browse my computer for driver software > Let me pick from a list of device drivers on my computer. Choose "Display Adapters" as Device Type and select Microsoft Basic Display Adapter.
11-28-2015 05:33 PM
I found this on a previous thread. Go to device manager -> display adapters -> right click on Intel (R) HD graphics 4000 or whatever -> update drive software -> browse my computer for driver software -> Let me pick from a list of device drivers on my computer -> select Microsoft Basic Display Adapter.