I hate to be constantly harping on the theme of broken Windows updates, but I recently ran into yet another issue on my workhorse notebook PC. Every once in a while, I will drill on the Update History link, like I did this weekend, choosing to ignore Window's cheerful assignment that my Windows was currently patched and any new patches would be promptly processed. It's difficult to explain why I didn't believe this, but I routinely bounce my PC and I hadn't seen any new updates over the past month or so. I was then dismayed to see the same cumulative monthly update had been failing nearly all month long on an almost daily basis (sometimes multiple attempts per day). I have no idea how this happens without Windows notifying the status on the update page and/or an explicit notification, say through the action center.
As Windows 10 owners may know, there's a troubleshoot link under the Settings/Windows Update page--which includes an Update Troubleshooter. Long story short, the troubleshooter did seem to find some corruptions which it later claimed to have resolved. But it seemed to cycle over the already downloaded patch, erring out as usual.
There is a well-known workaround to these type issues which is to turn off the BITS and WinUpdate services. delete the contents of the Windows Software Distribution folder and turn the services back up (see here for a related write-up).
The downside of this fix is you lose your history of recent patches via the Update History link. But the proof is in the pudding; Windows was finally able to download and process the update over a PC bounce.
So I would recommend, until Windows fixes its notification process, that you periodically review your Update History and check for a pattern of failing updates.
