Exception from HRESULT Excel Error: 0x800A03EC Repair

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The exception error HRESULT 0x800A03EC normally occurs when a variable is not declared in Microsoft Excel.

Description of the error:

An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

How to Fix:

Using the Task Manager

Log in to the server as an administrator.
Go to “Start” -> “Run” and enter “taskmgr”.
Go to the Process tab of the Task Manager and select’Show all users’ processes’.
If there are entries in the Excel.exe list, right-click on the entry and select Finish Process.
Close the Task Manager.
Go to “Start” -> “Run” and enter “services.msc”.
Stop the service that automates Excel when it runs.
Go to “Start” -> “Run” and enter “dcomcnfg”.

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This opens the Component Services window, expanded to “Console Root” -> “Computer” -> “DCOM Config”.
Locate “Microsoft Excel Application” in the list of components.
Right-click on the entry and select “Properties”.
In the properties dialog box, go to the “Identity” tab.
Select “The interactive user”.
Click on the “OK” button.
Switch to the service console
Start the Excel Automation service.
Test your application again.


1. Go to the File Explorer (you can open it from the Quick Launch toolbar or the Start menu).
2. go to the main area, press “This PC”.
3. In the context menu, specify the hard disk, memory card or other removable disk to be checked.
4. go to the Properties – Tools section.
5. Press Check in the Error Check section. The command is executed for users with administrator rights.
6. if no errors have been found, is perfect. If some are found, Windows should repair them while checking your hard disk.

The analysis process on the chkdsk graphical interface may take some time depending on the total space of the hard disk (or other device) on which it runs.

Clean Boot Windows


To restart under Windows 8 or Windows 10:

  • Press the “Windows + R” button to open a run box.
  • Type msconfig and click OK.
  • In the General tab, click on Selective Start.
  • Clear the Load Start-up Items check box.
  • Click on the Services tab.
  • Select the Hide all Microsoft services check box (below).
  • Click on Disable All.
  • Click on the Start tab.
  • Click on Open Task Manager.
  • In the Start tab, right-click on each activated start item and choose Disable.
  • Click on OK.
  • Click Restart.


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