Microsoft Outlook has built a strong reputation worldwide as a popular email client. People use it to send or receive emails for official or personal purposes. Outlook also works as a personal information manager, which makes it different from its rivals. Besides all the futuristic features, it also undergoes the Outlook error 0x80070021, due to which users cannot copy or create a backup of Outlook.pst files.

Often users report to us that whenever they try to backup or copy the PST files, Outlook shows an error 0x80070021. The primary reason for error occurrence is that the process has locked a portion of the file, which does not allow to copy the file to another location—facing a similar challenge? Need to send an immediate mail? Don’t worry! This article covers all the necessary precautions and measures that you need to perform to resolve the Outlook error code 0x80070021.


Why you encounter the Outlook error 0x80070021 and their preliminary fix 

Multiple reasons cause the outlook error code 0x80070021. A few of them are listed below, along with the preliminary solutions beneath them.

  • The portion of the file is locked, and hence you cannot copy the file to another location.
  • Solution: Use the steps as described in the further sections.
  • Another reason is an instance of MS Outlook is running in the background.
  • Solution: You will need to perform the clean boot, and you can follow the instructions from step one.
  • There is also the probability of a malicious attack that has corrupted the PST file.
  • Solution: Install trusted antivirus software on your computer to eliminate the corrupted PST file problem.
  • Your PST files are more than 10 GB, which has resulted in PST file corruption.
  • Solution: Ensure that the files do not exceed the 10 GB limit; you can split them into smaller parts as the large files are more prone to corruption.
  • You might have stored the PST files on the server, making it exposed to a network error or other technical glitches.
  • Solution: Storing the PST files in the server results in technical errors or network glitches, and hence you must store the PST files locally on your system.

Steps to fix Outlook error code 0x80070021  

The error code 0x80070021 doesn’t only appear in Outlook; instead, it can also occur in all the programs running in the background like Skype, Google calendar sync, etc. Follow the steps given below to eliminate the issue in Outlook.

Step 1. Clean boot your system 

The first type is to clean boot your system, and it should not be confused with safe mode. The clean boot makes your windows startup in a normal mode, and it doesn’t allow any non-essential, non-Microsoft background application. Here are the steps to execute the clean boot.

  1. Open the run dialogue box (use shortcut keys Windows + R).
  2.  Click the run field box, type MSConfig, and hit enter.
  3.  Now the task manager window opens, click the startup tab.
  4.  Click open task manager and select the services tab.
  5.  You will have to checkmark the option hide all Microsoft services box, click Disable All, and click Ok. (Do not forget this step, or else you might encounter the boot errors)
  6. After completing all the steps, the windows will start with a minimum number of processes, and after that, you can try to copy the PST files. If these steps do not resolve the problem, you will need to close the Outlook running in the background manually.

 Step 2. Stop Outlook that is running in the background 

  1. Go down and right-click on the taskbar.
  2. Now choose the options manager from the list.
  3. On the new screen, go to the processes tab, locate the Microsoft outlook, and click MS Outlook.
  4. Now choose the End task.
  5. Under the add-ins category, click Windows search email indexer.
  6. Ensure that COM Add-ins are selected adjacent to manage and click go.
  7. Now click Ok to confirm the selection.

Step 3. Open the Windows in Safe Mode  

You can also try to open the windows in safe mode and try to copy Outlook’s PST files.

  1. For that, all you have to do, click the Windows icon, hold the shift key, and click restart.
  2. Once you’re done with restarting, go to the option troubleshoot and select advanced options.
  3. Now you can select the see more recovery options and choose startup settings.
  4. Now select the restart button.
  5. You will see the startup settings list on your screen; press the number 4 key to enable safe mode.

Step 4. Uninstall the obsolete Microsoft Office communicator 

In several instances, the error 0x80070021 can also occur due to obsolete or outdated Microsoft office communicator applications. It conflicts with the new Outlook version resulting in an error.

  1. Firstly you will need to open the run dialogue box by pressing Windows + R keys.
  2. Now type appwiz.cpl in run dialogue and hit Enter.
  3. The programs and features window opens, locate MS office communicator from the list and click uninstall.
  4.  Now you can restart your computer to finish the uninstallation process.

Lastly, call the Outlook experts if error 0x80070021 doesn’t resolve 

These are the top four steps to help you eliminate the error code 0x80070021 in MS Outlook. Most users got relieved after using the initial first few steps. Apart from being effective, they are easy to implement as well. If you still face an Outlook error 0x80070021, that indicates the damaged or corrupted PST files. Get in touch with our experts to fix this issue and save your valuable time. Contact us now.