I'm not asking for technical help per se. Only HP and Nvidia can collaborate to resolve this.
Nvidia has ignored me and my requests for help. Nvidia provides drivers for notebook chipsets on their website, with a caveat that they don't 100% support them and scapegoat just to use the vendor's latest certified driver. Until the 387.92 Nvidia.com Notebook driver, when installed on a Envy 17t-u100, with 940MX, their drivers worked fine but with 387.92 and later produce a 'Code 43' in Device Manager for the Nvidia 940MX.
Nvidia alleges this is due to modified Video BIOSes, due to a change in how the driver handles voltages/clock speeds versus the user using a modified video BIOS to control the voltages for overclocking. This is not the case on my Envy 17t-u100, the Video BIOS nor machine has been altered in any way. They seem to bring up the 'Pascal' architecture being affected, but the 940MX is 'Maxwell'. I kept trying to tell them I have a Notebook and the VBIOS isn't altered, but I'm ignored.
I am currently running Windows 10 Fall Creator's Update (1709) with the latest driver 'certified' for the Envy 17t-u100 for 1703, 21.21.13.7699 (376.99), and while it works fine, who knows?
The main concern is that Microsoft keeps making drastic changes to driver archictectures , I want to be sure that my notebook will be supported for the life of and with Windows 10, Microsoft has taken an aggressive apporoach to denying installation of future updates if Microsoft determines if a single vendor of any user's hardware has discontinued supported.
The last HP I purchased was a g6-1b79us, and it still works. Even with the drivers as old as they are, they are 100% stable on the OS they were released for, but Microsoft thinks the $1200 I spent on my Envy 17t is just a cup of coffee.