There is a new major update to Windows 10 . The update is about 3GB .Make sure you have a fast connection and unmetered connection before you upgrade .Especially if you are using mobile broadband .
If you have just upgrade to Windows 10 less than 31 days ago.Please wait .Looks like you cannot go back to previous version of windows if you upgrade to this update . So hold back first as the update will not appear for you.
I tried the update for my tablet .But it was stopped halfway for no reason .I click “Check for updates” but the update does not appear again . Most likely I have to wait .
Go to Microsoft blog to see what are the changes .