"Up to date" even though I am running version 1507 (RTM build of Windows 10); how to get 1803 (Redstone 4)?

Well that edit is reassuring, and here I am with updated BIOS firmware. Everything seems to be working okay, now I just need to check a few more things and then I will perform an upgrade again.

As for the version, it does not tell me where you direct me to go, but I know for a fact that build 10240 (which I have according to WINVER.EXE) is version 1507, which is the official release of Threshold.

Interesting, mine looks a little different in the System section.

I suspect that MSInfo32 will not give you any more useful info. 

Yes, take all the driver & firmware updates that apply. It will be wonderful, if that is the cure.

(1) What version & OS Build is stated at "START, Settings, System, About"...?...

(2) Could be wise to make a Windows system image backup before doing the upgrade, at "START, Settings, Update & Security, Backup, Go to Backup & Restore (Win 7)".

Edit: That's right, even if no list exists for 1803 compatibility, the computer might be OK for it. Sounds good that a driver at its site mentions 1803 too.

Well right now I am getting updates for my BIOS (as it turns out, there is an updated version from over four years ago which I do not have) and my graphics driver (which supports 1803).

Now, I do not really think the hardware is incompatible; the system might not be supported for Windows 10, but if I follow a list of system requirements, of which my computer is el igible, then I should still be able to upgrade, right?

Once I get done with firmware updates, I will try other suggestions you mention before I attempt the 1803 update again.

UPDATE: My C: partition has 169 GB of free space, and running a hard disk drive check returned no errors.

(1) Ask Cortana for "MSInfo32". Then "System Model" should be the model number. Otherwise, see...

https://www.asus.com/us/support/Article/565/

How to Find Model Name

However, I can't find a list of ASUS models that are compatible with 1803 specifically. There are lists speaking of other versions of Windows 10, like...

https://www.asus.com/us/support/FAQ/1013416

Windows 10 - Which model supports upgrade to Windows 10?

But there will be a site for your ASUS model that will have firmware & driver updates. It's important to take at least the BIOS & other firmware updates that apply. Sometimes a computer will need them to be compatible with new Windows versions. Take the driver updates as well, if any. I would check that the driver is for a device that your computer actually has (shows up in Device Manager), because all computers of the same model may not be equipped the same. However, likely ASUS is smart enough that an inappropriate driver will simply refuse to install.

(2) Yeah, probably you've got plenty free on C:, or you'd be getting messages about that without even running the upgrade. Obviously, just open File Explorer to see how much space is free, though. Right-click C:, & select "Properties".

(3) If the RX 570 is easily unpluggable, I think I'd do that. I think the URL means easily unpluggable USB devices should be unplugged for the upgrade.

(4) For hard drive errors, I think the Windows way is sufficient. Right-click C: in File Explorer, & select "Properties". At the Tools tab, click "Check". Have it do the check, even if it says it is unnecessary. This will be speedy - just minutes compared to the hours of ChkDsk.  ChkDsk ran 12+ hours for me!

(5) It might be a good idea to do a Clean Start for the upgrade. It is easily undone afterwards.

(6) What is Redstone 5 - 1809? What did you do with that?