Click on the Search Area in Microsoft Windows 10:
Type in “Software Center”, in starting to type your likely to find it before completely typing the name of the software.
Click to Run
Once it is up and running you should be presented with a screen as below:
Click on “Operating Systems” on the left hand side:
Look for the following option:
Click to navigate into the upgrade and click install:
You will receive the following warning, please continue to “Install”:
This will appear throughout the upgrade process, it may take up to 2 hours at which time you will still be able to use the computer / laptop:
But be sure that as much as possible is saved as it will eventually lead to a restart of the computer/laptop, to be cautious if the upgrade process reports over 70% then save everything that requires saving and allow the update to take its course.
For those of you who have updated or are about to update to 21H2 here are the reported issues and how to fix them:
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Go to Windows Update, choose "update online" and allow the device to download and install updates.
See: Manual Windows Updates - Helpdesk - Swansea University Medical School Confluence Site