How to Resolve “Outlook Express Could not be Started” Error

By | August 24, 2011

Outlook Express is the free email client that comes with various versions of Windows and Internet Explorer. Outlook Express uses .dbx files to store all your mailbox components and a master folders.dbx file contains the tree structure of all your mailbox folders.

Some times when you attempt to start Outlook Express it fails and shows this error message

“Outlook Express could not be started because Mose.dll could not be installed. Outlook Express may not be installed correctly”

At this point you may feel strange because it’s been such a long time that you are using Outlook Express and now suddenly, it start showing message of “not installed correctly”.

This message means that some file is missing which does not allowed to open Outlook Express. It must be your folders.dbx file that get corrupted, deleted, or marked read only due to some virus infections or hardware/software related issues.

Resolution: Follow below steps to resolve this error message:

1. Check whether the DBX file is being deleted

Default location of DBX file C:\Documents and Settings\[Your user name]\Application Data\Identities\{…}\Microsoft\Outlook Express

If file is being deleted, use system restore to get your folders.dbx file and mount it to the default location and restart Outlook Express. If file is being available, move to 2nd step.

2. Check whether it is being marked read only. Right click in the folders.dbx file and check the properties. If it is marked read only, uncheck that option and check Read & Write, Apply the changes. If it is not marked Read only then it seems that the folders.dbx file get corrupted. In such a case of corruption, move to 3rd step.

3. Outlook Express does not comes with any built-in tool to repair DBX file. So in this case you need to create new folders.dbx file. To create new folders.dbx file, Rename the old file or move it to other location and restart OE, it will automatically creates new folders.dbx file.

As Outlook Express does not have any built-in tool to recover DBX file, you need to use third party Outlook Express Recovery tool to recover folders.dbx file. These tools are able to recover DBX files in any instance of corruption.


This article is written by Stephen Lembert. He is a data recovery expert and now writes about email recovery such as Outlook Express Recovery, Outlook email recovery, Entourage Recovery, Lotus Notes Recovery etc.