How to Fix “Cannot start Microsoft Outlook” & “Cannot open Outlook window”

Despite being one of the most widely used emailing applications, MS Outlook often faces unexpected bugs and errors. One of the most frequent errors is “Cannot start Microsoft Outlook”. This error can be resolved by fixing issues within PST file.

We recently came across a sudden spike in user queries on technical forums reporting that they faced the “Cannot start Microsoft Outlook” error more than once. This led us on a fact finding mission wherein we investigated the reasons behind this error and its most effective solutions. The results of our investigations have been described in this post.

The Error and its Triggers

When trying to launch MS Outlook by double-clicking on its icon, if you receive an error that says, “Cannot start Microsoft Outlook” or “Cannot open the Outlook window”, this is why it could be happening:

• A corrupted XML file in the Navigation Settings folder could be setting off this error. The easiest way to detect this is to check the size of the XML file. If its size is 0kb, it means that it has been compromised.

• If you are running Microsoft Outlook in compatibility mode, there are chances of Outlook not starting.

• Microsoft Outlook can refuse to start even when you use an old profile on an older Outlook version.

• Often we uninstall applications and reinstall them on the machine. When uninstall and reinstall procedures are not performed properly, they might cause Outlook to not start.

• If any Outlook file (even the settings file for that matter) becomes damaged or deleted, it will corrupt the entire application and cause it to not open.

How do you get rid of an error that gives you such limited information with no clue as to its resolution? Read on to find out.

Easy Ways to fix “Cannot Start MS Outlook” error

To help you fix this error, we have compiled a set of procedures. Perform one of the following procedures to recover your MS Outlook application.

Recover the Navigation Pane settings file

One of the main reasons of not being able to open MS Outlook is corruption of the Navigation Pane settings file. Recover this file by performing the following procedure:

1. In the Start field, type Outlook.exe/resetnavpane.
2. Select the file and launch the Outlook application.

If this doesn’t recover the file, delete the file as follows:

1. In the Start field, type %appdata%\Microsoft\Outlook. The system lists all the configuration files in Microsoft Outlook.
2. In the Search field, type the name of the Outlook XML file.
3. Right-click the XML file and select Delete.

Note: As a first step always try to recover the XML file. Only if you are unable to recover it, perform the delete procedure.

Recreate a new profile

Recreating a new Outlook profile and importing all your old data to it often removes problems within Outlook, so you can try this next. To recreate a new profile:

1. From Start, go to Control Panel -> Mail.
2. To add a new profile, in the Mail window, click Data Files > Add.
3. Set your newly created profile as the default profile.
4. Launch Outlook. Outlook should open the new profile.
5. To import the old data into the new profile, open the Outlook window.
6. Click File -> Open -> Import -> Import from another program.
7. Select the old data file and click on Next.
8. After the system completes the import procedure, click Finish.

Turn off Compatibility mode in Outlook

Sometimes, if Outlook is running in Compatibility mode, it can face problems in starting. To turn off the Compatibility mode:

1. In the Start field, type exe.
2. Select the Outlook.exe file and right-click the file.
3. Under the Properties tab, select Compatibility.
4. Clear the Clear the compatibility mode checkbox.
5. Click OK.
6. Restart the Outlook application.
7. If the compatibility mode is still on, search for the PST file.
8. Select Restore previous versions.

Open Outlook in Safe mode

When everything else fails, try opening Microsoft Outlook in the Safe mode to resolve the “MS Outlook Cannot Start” error. Here are the steps to do this:

1. In the Start field, type Outlook /safe.
2. Press the Enter key.
3. When the system prompts to know if you really want to open Microsoft Outlook in the safe mode, click on Yes.

Repair Outlook data file

When the Outlook data file (PST) is corrupted or damaged, often resulting from an improper uninstall of a previous version it stops Outlook from opening. To repair a damaged Outlook data file, perform the following procedure:

1. From Windows Explorer, go to Program Files -> Microsoft Office.
2. In the Search field, type exe and locate the SCANPST.EXE file.
3. Double-click the SCANPST.EXE file and browse to the location of the PST file.
4. To begin the scan, click Start. If there are errors in the PST file, the system will display the following message in the Microsoft Outlook Inbox Repair Tool dialog box:

Errors were found in this file. To repair these errors, click Repair.

5. Click Repair. After the repair is complete, launch your Outlook application with the PST file.

While the Inbox Repair Utility (ScanPST.exe) is an efficient tool to detect and fix PST file problems, it fails to repair severe corruptions. In such cases, a great alternative to it is reliable third-party PST repair software, Stellar Phoenix Outlook PST Repair. This competent tool enables you to scan corrupt PST file and repair it to recover all contents such as e-mails, attachments, contacts, calendars, tasks, notes and journals. The repaired email items are saved as a new usable PST which can be directly imported into MS Outlook.