Why does "search for updates" never return?

I'm running Windows 10 Home 64-bit build 1709 on one of my laptops. I know it's overdue for an update so I tried to deal with that today; I went into Settings/Update and Recovery and then searched for updates. Unfortunately, it never comes back; after 15 minutes and more, it is still searching. I've got a 35mpbs fibre optic connection so it should have returned long ago, in my opinion.

How do I get a list of updates so that I can actually begin the update process?

Not having had an automatic upgrade to 1803 indicates that there was/is an underlying problem.
To generate the best error code, attempt the upgrade using an iso.

Find two flash drives that you can format: (> or = 8 GB)
Create a bootable Windows 10 iso:
Download Windows 10 ISO File
https://www.microsoft.com/en-us/soft...load/windows10

Perform an in place upgrade repair with the windows 1809 iso:
Repair Install Windows 10 with an In-place Upgrade

If the in place upgrade fails with the 1809 iso:

a) run setupdiag > post a share link for the results into the thread:
https://docs.microsoft.com/en-us/win...rade/setupdiag

b) post the error code and message into the thread

c) list all non-Microsoft:
antivirus software (always on and manual)
firewall software
drive encryption software

d) create a bootable windows 1709 iso:
Windows Download - #1 Windows ISO Download Source
Microsoft Windows and Office ISO Download Tool
TechBench by WZT (v4.1.1)


If reinstalling drivers and applications is a viable fix then you can perform a reset save files or equivalent.
This is a trade-off (time spent troubleshooting versus time to perform the reset, install drivers, and applications, and time to re-customize windows and replace browser bookmarks.

It turns out I gave up prematurely. I let it run for another hour and somewhere in there, it came back with a list of updates, although none of them seem to be Windows proper; they're almost all updates for Word, Excel and other apps, plus the Malicious Software Removal Tool, which is first on the list. Unfortunately, there's an exclamation point circled in red beside the top of the list; the first item says "Status - installing - 0%"; all the others say "Awaiting install". Does that change anyone's advice on what I ought to do?

Also, I'm not sure if this is related or not but I keep getting notifications from Logitech about updating the software for the external webcam I have but every time I click on it, it shows me a list of updates that is empty. When I close out of that - I can't select anything since the list is empty - it sends me another notification telling me about its updates.

I should mention something. The laptop that won't update is only used very sporadically, once a month for a few hours. I use it to video-conference for my monthly book club meeting and we don't video-conference every month. There's rarely free time to do updates at the meeting so that's why I've fallen behind.

The options for a failure to upgrade Windows 1709 are:
a) reset save files or reset save files equivalent > reinstall drivers and applications > re-customize windows > restore bookmarks
or
b) troubleshoot performing an in place upgrade repair to generate an error code and error message > troubleshooting steps based on the error code and message
or
c) clean install if files are backed up

It seems appropriate to update this thread.

I didn't tackle the steps you recommended immediately, since I was trying to finish something on the computer I use most. Yesterday afternoon, I glanced over at the laptop that wouldn't update and noticed that the update page indicated that it was downloading updates! It was downloading *VERY* slowly but downloading nonetheless. It took half the afternoon and all evening to finally reach 100% and then it started rebooting. Given the volume of updates, I did not stay up until it finished, which is a good thing since it apparently took a solid 3 hours. This morning, I got a normal signin screen and the computer is behaving normally. The update page declares that I'm "up to date" at version 1803. I've just finished another search for updates and its come back with another long list that is already partially downloaded.

Bottom line: I don't know what was wrong or why it took so incredibly long to grab all those updates but it seems to be fixing itself. I'm just going to keep searching for updates until it tells me there aren't any left. Then I can get started on the OTHER laptop, the one that's gone into Recovery mode. I'll post back here if there are any further hitches to seek your guidance.

The update to 1803 completed okay but when I look for further updates, it says I'm already up-to-date. I know that's not true - the computer I'm writing this from is at version 1809 and I'm not sure if there is a further update after that.

Do I just leave it at 1803 or do I need to do something to nudge it ahead to 1809 or later?

Consider making a backup image:
Backup and Restore with Macrium Reflect

These are links for Windows 1903:
Current Status of Windows 10 October 2018 Update version 1809
Known issues for Windows 10 May 2019 Update version 1903

Thanks, Dalchina, that's very useful to know. Am I correct to assume that I should just leave things alone at 1803 and let Windows itself decide when the update to 1903 (or later) is appropriate?

Also, zbook, what do these lists of issues mean when they say something is "mitigated"? My understanding of the word is that it means things are better than they were initially but are NOT fully solved? If that is the case, then I'm not inclined to install 1903 until all or most of those issues are "fixed" or "resolved" or whatever term they use to mean fully-repaired.