This vid contains complete solutions that helps fix error code 0X80070020 while trying to upgrade yr current system to Windows 10, or update yr Windows Phone, play/run some app for WP, and/or back up your system.

Useful links:
* Try this uninstall tool PRO@ https://macpaw.7eer.net/c/376211/297731/1733 if you can’t uninstall your security program yourself.
* Download & run Media Creation Tool@ http://go.microsoft.com/fwlink/?LinkId=691209
* backup files: https://answers.microsoft.com/en-us/windows/wiki/windows_10/how-to-manually-backup-and-restore-your-files/45859954-c9c3-403f-b997-e96c8e001963
* 10 Tips before installing Windows 10@ https://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/how-to-10-tips-before-installing-the-latest/4fbec413-fed4-4a18-b1de-399a2d1e2a3a
* download official Windows 10 ISO file@ https://www.microsoft.com/en-us/software-download/windows10ISO/
* If U choose to upgrade from previous versions of Windows using Windows 10 ISO file: https://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/how-to-upgrade-from-previous-versions-of-windows/31722b30-1da9-42bb-b331-0edc4649bf43
* Update troubleshooter for Windows 7 & 8 https://support.microsoft.com/en-us/kb/2714434
* Update troubleshooter for Windows 8.1: http://windows.microsoft.com/en-us/windows/troubleshoot-problems-installing-updates#1TC=windows-8
* Troubleshoot common Setup and Stop Errors during Windows 10 Installation: https://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/how-to-troubleshoot-common-setup-and-stop-errors/324d5a5f-d658-456c-bb82-b1201f735683

* For Windows Phone users, try: Backup yr data and perform a hard reset later:
a. http://www.pcadvisor.co.uk/how-to/mobile-phone/how-backup-restore-windows-phone-8-3581648/
b. https://support.microsoft.com/en-us/help/10768/windows-10-mobile-reset-my-phone

If U met said error when backing up yr system:
* https://www.winhelp.us/configure-automatic-backup-in-windows-7.html
* http://superuser.com/questions/508932/windows-backup-failed-with-error-0x807800c5 & * http://www.howtogeek.com/131541/how-to-use-windows-7s-backup-tools-in-windows-8/ Learn more?

* https://www.youtube.com/watch?v=Tndrf-TpLmU Fix error code 789/809/810
* https://www.youtube.com/watch?v=8ntbKE76iuI Fix error code 0x80004005
* https://www.youtube.com/watch?v=Zd7tm4OE-9w Fix 0x80070002

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