Since installing Fall Creators Win 10 final release after various Insider releases, I find my PC takes a couple of minutes to boot from power on. The hardware is the same but earlier Win 10's were a lot faster.
My specs are here http://speccy.piriform.com/results/EVFBXGdtOpGZlZ47GkUfh3T
Try to configure the system with Clean Boot, if Clean Boot model is faster than normal boot, please narrow down the problem via re-enabling boot item one by one.
Perform a clean startup to determine whether background programs are interfering with your game or program: https://support.microsoft.com/en-us/help/331796/perform-a-clean-startup-to-determine-whether-background-programs-are-i
Besides, check/install available update/hotfix using system built-in Windows Update, as Fall Creators Update has been installed, OS Build 16299.125 is the newest until now.
December 12, 2017—KB4054517 (OS Build 16299.125): https://support.microsoft.com/en-us/help/4054517
