[Resolved] How to Fix Error 0x80070021 in Outlook 2016/2010/2007

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  • Published on
    August 20th, 2018
  • Updated on
    September 8, 2022
  • Read Time
    4 minutes
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Outlook is a requisite program offered by Microsoft and utilized by a series of users are for sending and receiving email messages. It is also used to perform tasks, Todo notes, maintain calendar, contacts, journals and so on. Yet, do you know when you are working Outlook you may experience a few errors by your accidental actions? One such frequently asked query on Microsoft Outlook error “how to fix error 0x80070021 in Outlook 2016” is discussed here. The causes for such error could be many but mostly appears when you attempt to back up Outlook.pst.

win download

Query scenario:  When I attempt to backup or copy my outlook.pst file onto another system location I am getting “error 0x80070021″ saying the process cannot copy the file as another process has locked a portion of the file. How to fix this error code 0x80070021 when appears in Outlook?”

Measure  precaution to avoid error code 0x80070021 in Outlook

This problem is frequently faced by Outlook or any other windows program that uses a feature of running in the background. Applications like Skype, Google Calendar Sync, Microsoft Office Communicator could be at the center point of this error. What measure should be taken to get rid of error 0x80070021 in Outlook? See the following points:

  1. As you know Outlook 2013 && 2017 supports PST file size of 20GB and Outlook 2010, 2013 & 2016 supports 50 GB. Always work on a safer side by limiting the Outlook PST by not exceeding you files size beyond 10GB to prevent it from corruption.
  2. Avoid abnormal closing of Outlook platform that may cause damage to your Personal PST folder.
  3. In Microsoft Outlook2002 which can only support PST file size 2GB, try to keep your file of pre-sized under 2GB and avoid error code 0x80070021.
  4. Storing PST files on the server is always a bad choice when coming to safekeeping your Outlook data file. Always save your file on your desktop itself to avoid corruption error(Error 0x80070021 in Outlook).
  5. Install a good antivirus on your system to get rid of virus attacks and other corruption issues.

You may also like to read: Solve Error Cannot start Microsoft Outlook

How to Fix Error 0x80070021 in Outlook 2016

Follow the Step explained below:

Task Manager

  • Press Ctrl + Alt +Delete and open Task Manager Or Right click on the taskbar of the desktop and choose Task Manager Option.
    start task manager
  • Under Processes tab, look for applications such as Outlook process and Click on it.
    open task manager
  • Select End Task.

Restore Point

  • Log into your system as an Administrator.
  • Click Start Button on the desktop >> Click on All Programs Option >> Windows Accessories >> System Tools >> System Restore.
  • Now select “Restore my computer to an earlier time”
  • Under the option on this list, click a “restore point”, and select the latest system restore option and click on Next.
  • Click Next on confirmation window.
  • Restart your system when the restoration process is completed.

Remove Indexing Tool

  • Open Outlook, go to Tools on the Menu bar.
  • Click on ‘Trust Centre’.
  • On the left-hand pane, choose Add-Ins and then near the bottom of the window, you’ll see a button that will let you manage your COM Add-Ins.
  • Ensure that you have selected ‘COM Add-Ins’ from the drop-down box and then click GO.
  • Highlight Windows ‘Search Email Indexer’ and then click ‘Remove’.
  • Click OK and then close Outlook.
  • Re-open Outlook and run the backup. (The program recommends that Outlook needs to restart before backing up)

Try all the steps and recommend to restart the outlook or the computer to have changes effect upon next login.

Using SysInfo Outlook Repair Tool

  • Download and install Outlook Repair software.
  • Add PST file stored on your system. Select the scanning mode and suitable option and click OK.
    repair PST file
  • Once the scanning is completed, you now preview your files or emails in your file.
    peview the repaired PST file
  • Browse a destination path to save the recovered. Also, select the file type to save the PST file (or you simply select PST file type) ClickOk.
    save PST file into another format
  • The file will be saved at the destination path of your select file type.

Also read: Outlook Encountered A Problem and Need to Close


Errors message is a common issue faced by almost every outlook users. Well if you are getting outlook error code 0x80070021 saying messages like your part or your file is locked or blocked for further access. For the I have discussed every possible solution for the error 0x80070021 in Outlook, try out any of the above explained in this article. Either the manual procedure or with the help of SysInfo Outlook Repair Tool. It is an amazing software which easily repairs all the damaged files, and fix error 0x80070021 in Outlook and recovers files from severe corruption.

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