I've been trying to update my PC for a while now and it seems like it just refuses to update and stalls either at 99% or 0%.
I've tried clearing the update cache (C:/Windows/SoftwareDistribution + net stop wuauserv) which doesn't seem to work.
I've also tried updating to anniversary edition which also failed.
I don't really have the exact error codes but I do recall something along the lines of FIRST_BOOT, it hung on the screen with the blue windows logo and the loading dots for 5+ hours.
I've tried to download the updates manually from the Microsoft update catalog, letting windows update run for 10+ hours, and some other stuff.
My winver is showing up as Version 10.0 (Build 10240).
I built the PC myself, specs are as follows:
Motherboard: GIGABYTE GA-X99-UD4
GPU: 2x EVGA GeForce GTX 980
PSU: EVGA SuperNova 1300
CPU: Intel i7-5938K
SSD: 2x SAMSUNG 850 EVO
RAM: G.SKILL Ripjaws 4 Series 16GB
HDD: Seagate Desktop HDD 3TB