Windows will not update after 10586

Hi,
Please do a basic check on our disk: download Hard Disk Sentinel (trial) and run that; post a screenshot of its GUI to check your disk. If failure is indicated, do not proceed.
to post a screenshot please use the Insert Image icon above your post to the left of the video icon

I'm wondering why you are using such an old build- have you had Windows update disabled?

Then:

First, I would advise you to take due precautions (this should be something most people do routinely as all regular contributors here do).
Things can go badly wrong- at any time, not just when upgrading.
Create (or update if already using it) a disk image to a large enough external drive.
E.g. Macrium Reflect (free) + its boot disk + external storage for disk image sets - use option Backup, Windows Backup.

With disk images you can
- recover to a new disk if your disk fails
- restore to a new PC if if is stolen
- restore an unbootable PC to a previous working state
- extract files from the images - a complete backup
- etc..

Second, to avoid the repeated downloads, and give you control, and also a bootable Win 10 medium - useful for certain types of repairs- please do this:

================= Manual installation ===========
1. Get the iso file
Download Windows 10 ISO File Windows 10 Installation Upgrade Tutorials
2.
Create Bootable USB Flash Drive to Install Windows 10 Windows 10 Installation Upgrade Tutorials
- (or, simpler, a DVD if you have a DVD drive)
3. When ready, attempt the upgrade
Upgrade to Windows 10 Windows 10 Installation Upgrade Tutorials

Third: a number of people have found the update failing in this way. Two causes I've noted (many possibilities):
1. Disable Defender if using it - or uninstall any AV you are using.
2. Weird partition structures.

Try (1) and then try upgrading again (after you've created the disk image as above).

If no luck:
Please post a screenshot of Disk Management
Windows key + X, click Disk Management
to post a screenshot please use the Insert Image icon above your post to the left of the video icon

Time for a new drive :) Hard Disk Sentinel is a very good program, I`ve been using it for years. If any drive in my system goes below 99% health, it gets pulled. I`m a bit OCD when it comes to my PC

You need to get more airflow on your hard drive.

Macrium is very easy to use, just take your time with it.

Hi, your disk is ok- for now- but as AddRAM says, there is a risk, so needs monitoring.

That emphasises the need for a disk image backup.

My guess is you have no backups- so what will you do when your disk fails? Or your PC becomes unbootable?
These things happen- I've seen people in tears when they've realised they've lost precious material.

It's also a lot more technically demanding to clean install Windows and all your programs onto a new disk, than to restore a disk image- and it takes a lot more time too.

Macrium is fairly easy to use once you've used it- the concept of disk imaging takes getting used to.
There are very simple videos on this site.
Windows 10 instructional videos by Ten Forums members Solved - Page 69 - Windows 10 Forums

To create your first base image, plug in an external disk, launch Macrium, click Backup, click Windows Backup

Thereafter, you create a (smaller, faster) differential image - the changes with respect to the base image.

To restore - you need a base image, or the base image + any differential image.

There's lots of help, guides, videos on Macrium's site.

There are other programs such as Aomei Backupper (and Easeus and Acronis) but most here like Macrium.
Veeam Endpoint has also been recommended. Veeam and Aomei have a simpler GUI.

Help in Macrium takes you here:
Macrium Reflect v6 User Guide - KnowledgeBase - Macrium Reflect Knowledgebase

Buying disks
- relatively easy- under £40 for a USB 1Tb hard drive, under £65 for 2Tb as a very rough guide.
Amazon, Ebay... a shop... other online places.

You will need either a DVD (I assume the creator's build fits on a DVD - not tried yet) or a USB flash drive >4Gb for Windows installation.