What should I do if win8.1update fails to install?

What to do if the win8.1update installation fails:
Win8.1 Update has been officially released, but many users have encountered download problems and cannot download from Windows Update at present. The Win8.1 user of the Microsoft Community Forum said that Windows 8.1 Update could not be installed, error code 80070020, and no other specific information was provided to the user.

Microsoft has not released a patch to solve the Win8.1 Update problem encountered by users, but users who cannot get the update can manually download the update package. For details, please refer to: win8 system upgrade to win8.1update graphic tutorial < Br> Some users on the Microsoft forum wrote:
“ I have tried to install Win8.1 Update for a few hours. Earlier today I installed a series of files using Windows Update. Later I tried to install the upgrade file KB2919355 that appeared in Windows Update. The 800MB file download took 45 minutes and my network speed was 20 MB/s. The error code 80070020 appeared after 20 minutes of installation. Then I rebooted, but nothing changed or improved. ”
It is not clear how many users are experiencing this situation. Obviously, some Windows 8.1 users cannot upgrade properly.