
Not Ing Windows 10 20H2 December
Microsoft have deleted it from Windows Update Catalog since is was replaced by the latest version Windows 10 2004.Issue downloading windows 10 20H2 December Cumulative update (KB4586853).
Now, within the Settings page click on Update & Security. The May 2021 Update is available initially to select devices running Windows 10, version 2004 or later who are interested in experiencing the latest feature updates and are ready to install this release on their device. If you would like to install the new release, open your Windows Update settings ( Settings > Update & Security > Windows. If you need Windfeature update, we need to download package KB4517245.
It have been like for several hours. Please solve this issue soon.Windows Update shows that your device is up to date and no new updates are available even if they are using an older build of Windows 10. If you are also facing this problem and Windows 10 new builds are not appearing on Windows Update in your computer, following steps will help you in fixing the issue and downloading the RTM build without any.

In order to safeguard against this type of thing, Windows will usually create a restore point just before applying an update, so you can roll it back if there are any problems. After the update installs, you can restart Windows to exit Safe Mode.Step 4. Perform a System Restore. Accessible from the Startup Settings menu, this mode disables everything but the absolute essentials Windows needs to run, ensuring that any software conflicts that could be interfering with the update are removed.
Be warned, though, that this will erase your entire hard drive, so make sure that any vital data is as thoroughly backed up as possible beforehand. This is pretty much the 'nuclear option', but if all else fails, you may be forced to simply erase your previous copy of Windows and simply start from scratch. A more in-depth fix than just doing a System Restore, the Startup Repair tool (also accessible from the Advanced Startup Options screen) can sometimes fix underlying issues that may be hampering the update process.Step 6. Perform a clean Windows installation.
