- If Outlook won't open in Windows 10 or 11, the likely cause if file corruption or corrupted profile.
- You might want to disable the add-ins from Outlook in order to fix this problem.
- Using a Run dialog to reset the software is a great way to fix any issues that you have.
Microsoft Outlook is one of the most used email clients on the Windows 10 platform with millions of users worldwide.
Unfortunately, many users reported that Outlook won’t open on Mac or on their Windows 10 PC. This isn’t the only problem and users also reported that Outlook is running slow on Windows.
This can be a problem especially if you use the software frequently, so let’s see how to fix it using our complete guide below.
Why won’t Microsoft Outlook open?
There are multiple reasons for this issue, but the most likely cause are your add-ins, so you might have to disable them to fix the problem.
File corruption can affect both your profile and your Outlook data file, so recreating them might be necessary. In this guide we’ll go through all possible solutions to this problem, so keep on reading.
What can I do if Microsoft Outlook will not open?
- Start Outlook in Safe Mode and disable add-ins
- Create a new profile
- Repair your Outlook data file
- Use the /resetnavpane command if Outlook 2010 won’t open
- Try an alternative email client
- Make sure that Outlook isn’t running in Compatibility mode
- Use Microsoft Support and Recovery Assistant
- Change the DPI settings
- Log out of iCloud
- Use the New Email Message option
- Use a separate password for Outlook
- Try using an older version of Outlook
- Change the way you close Outlook
- Try to send any file with Outlook
- Delete Outlook App Data folder
- Check if you have permissions to access your PST file
- Run the sfc /scannow command
- Delete the registry key
- Remove the VPN software
- Reinstall Outlook
1. Start Outlook in Safe Mode and disable add-ins
1.1 Start Outlook in Safe Mode
- Press Windows key + R, enter Outlook /safe, and press Enter or click OK.
- When Choose Profile window opens, click OK.
- If you’re asked to enter a password, be sure to enter it and click Accept.
1.2 Disable add-ins
- In Outlook choose File and select Options. Now go to Manage Add-ins.
- In View and manage Office Add-ins, make sure that the Manage box shows COM Add-ins and choose Go.
- Remember the list of all enabled add-ins in the Available Add-ins section and disable all the selected add-ins by clearing the checkboxes. Click OK.
- Now close Outlook.
1.3 Start Outlook and enable the add-ins
- Press Windows key + R and enter outlook. Press Enter.
- Choose File and go to Options. Now pick Manage Add-ins and enable one or more add-ins on the list.
- Close Outlook and restart it.
- Enable another add-in and repeat the Outlook restart cycle. Perform this step until you find the problematic add-in and keep it disabled.
Many users love using add-ins to enhance Outlooks functionality, but sometimes add-ins can create certain problems and prevent Outlook from starting.
Since you’re not able to start Outlook normally, your only solution is to start Outlook in Safe Mode and disable the add-ins as instructed above.
According to some users, the problem was Microsoft CRM Add-in, and after disabling it the issue was resolved.
Outlook won’t open in safe mode? Few users reported that they were unable to do so when using the Outlook /safe command.
If you’re having the same problem, be sure to enter the full path to the outlook.exe file in the Run dialog.
Instead of Outlook /safe, you should use the following command:
C:\Program Files (x86)\Microsoft Officeroot\Office16\OUTLOOK.EXE /safe
Keep in mind that the path to outlook.exe might be different on your PC, so double-check if before you use this command.
2. Create a new profile
- Start the Outlook app from Windows 10.
- Click the Show Profiles button and choose Add.
- Enter the name of the new profile.
- Enter your name, email address, and password and click the Next button. This method will set up all the necessary email settings manually. If you want, you can also choose the option to manually set up your Outlook profile.
- Click Finish and the new profile should be added to the General tab in the Mail dialog. Select Prompt for a profile to be used option and choose OK.
Your Outlook profile keeps all your settings, but if for some reason your profile gets corrupted, Outlook won’t open when loading your profile, so you’ll have to recreate it.
If everything works without any problems with your new Outlook profile, you can now switch back to the original Outlook profile and check if the problem is completely fixed.
3. Repair your Outlook data file
3.1 Scan your Outlook data file
- Go to your Office installation folder and run scanpst.exe.
- Click the Browse button and select your Outlook data file.
- Click the Repair button to scan your data file.
- If any errors are found click the Repair button to repair them.
3.2 Delete the files from Microsoft Exchange
- Go to Control Panel and select Mail.
- When the Mail window opens, select E-mail Accounts.
- Go to the Data Files tab, select the Exchange account.
- Now choose Open File Location.
- A new Explorer window will open. Close the Mail window and switch back to the Explorer window. Locate the data file and delete it.
If you use Microsoft Exchange, you can simply delete your data file and it will be recreated again.
After deleting the file, it will be created again with Microsoft Exchange once you start Outlook.
All your Outlook email messages, contacts, tasks, and events are stored in your data file. Sometimes the data file can get corrupted and that can prevent Outlook from opening.
Speaking of the Outlook data file, there are many reasons why it can’t be accessed. We have a great guide on what to do if the Outlook data file cannot be accessed.
For a quick fix to the problem, you need to repair your data file by following the steps above.
4. Use the /resetnavpane command if Outlook 2010 won’t open
- Make sure that Outlook is completely closed.
- Press Windows key + R, enter outlook.exe /resetnavpane and press Enter to run it.
- Outlook should now open.
If Outlook won’t open on your Windows 10 PC, you might be able to fix it by running /resetnavpane command.
By running this command you’ll remove all customization related to the navigation pane, and sometimes that can fix this problem with Outlook.
5. Try an alternative email client
If your Outlook won’t open emails, perhaps it’s time you changed the email client altogether since there are many great alternatives available that can replace it.
Our suggestion in this particular case would be Mailbird. Currently, Mailbird is one of the most popular email clients and also one of the best email apps for Windows 10.
The tool comes extremely handy, syncing all your emails and contacts from multiple accounts in one unified Inbox. Plus, it brings a lot of easy-to-set customizable features and options to serve the mentioned purpose.
Users praise Mailbird for the minimalist user interface, its low impact on the system, plus the ease to use a lot of convenient shortcuts.
6. Make sure that Outlook isn’t running in Compatibility mode
- To do that, simply right click the Outlook shortcut and choose Properties from the menu.
- Go to the Compatibility tab and make sure that Run this program in compatibility mode option isn’t turned on.
- Click Apply and OK to save changes.
Compatibility mode is designed to run older software on Windows 10 that usually wouldn’t run natively. Outlook is fully optimized for Windows 10, therefore there’s no need to use Compatibility mode.
In fact, if you have Compatibility Mode turned on for Outlook, you can sometimes cause this issue to appear, therefore it’s advised to turn Compatibility mode off for Outlook.
7. Use Microsoft Support and Recovery Assistant
Sometimes you can fix Outlook errors simply by running the Microsoft Support and Recovery Assistant tool.
This tool is designed to fix common problems with Office tools and in order to fix those problems, you just need to download it, run it and let it fix the problem for you.
8. Change the DPI settings
- Right-click your desktop and choose Display Settings.
- When the Display Settings window opens, move the slider all the way to the left until it says 100%.
- After that, log out of Windows 10 and log back in. Try to start Outlook and check if the problem is resolved.
Few users reported that you can fix the problem with Outlook simply by changing the DPI scaling to 100%.
Few users reported that they managed to fix this problem simply by lowering the display scaling to 200 DPI from 250 DPI, so you might want to try that as well.
9. Log out of iCloud
iCloud is a popular cloud storage service created by Apple, but unfortunately, this cloud service can cause some issues with Outlook.
If Outlook 2010 won’t open, you just need to log out of iCloud and log back in and you should be able to start Outlook without any problems.
10. Use the New Email Message option
- Press Ctrl + Shift + Esc to start Task Manager.
- When Task Manager starts, in the Process tab locate the Outlook process and click the End Task button.
- Close Task Manager.
- Locate Outlook in Start Menu and click the right arrow next to it to open its Jump List.
- You can also right-click Outlook on your Taskbar to reveal its Jump List. Select New Email Message or New Meeting or any other option. A new window will now open.
- After that, right-click Outlook and choose the Run as administrator option. Outlook should now start without any problems.
Some users are also suggesting changing the File open on start option while using this method.
- Select the New Email message from the Jump List.
- When Outlook opens go to Settings, select Advanced and change File open on start to Outbox.
- Restart Outlook and change File open on start to Inbox.
- Save changes and the problem should be resolved.
If Outlook won’t open from Taskbar, then this method might be useful as a workaround, so there’s no reason not to try it.
11. Use a separate password for Outlook
Users reported that you need to use a separate password for your Outlook account if you use 2 step verification with your Gmail account.
To fix this problem simply generate a 16-digit App password that you will use with Outlook. After using the new password with Outlook, the issue should be resolved.
Some users are also suggesting removing your Gmail account from Outlook as a potential workaround, so you might want to try that.
12. Try using an older version of Outlook
Users reported that Outlook 2010 won’t open on their PC, but one suggested workaround is to use an older version of Outlook with your PST file.
If you have an older version of Outlook available, you can use your PST file with it without any problems.
All your emails will be imported and you can continue where you left off. This isn’t a permanent solution, but it’s a useful workaround.
If that doesn’t work, you can try using a different email client as mentioned in the first solution. There are many free alternative mail clients that will do perfectly as an Outlook replacement.
13. Change the way you close Outlook
This is another workaround, but users reported that it works for them. Apparently, you can stop this error simply by choosing the File and then selecting the Exit option to close Outlook.
According to users, this error appears if you use the X button to close Outlook, therefore instead of closing Outlook with the X button, try closing it by with a different method.
Users reported that this workaround works for them, so you might want to give it a try.
14. Try to send any file with Outlook
Users reported that they are getting stuck on a Processing screen while trying to start Outlook. One suggested workaround that might work for you is to try sending any file using Outlook.
To do that, start Outlook and you should get stuck on the Processing screen.
After that happens, open File Explorer and right-click on any file and choose Send To – Mail Recipient. After doing that, a new email window will open along with Outlook.
15. Delete Outlook App Data folder
15.1 Delete the Outlook folder
- Make sure that Outlook is completely closed.
- Press Windows key + R and enter %localappdata%.
- Navigate to Microsoft folder.
- Locate the Outlook folder and delete it.
- Try to start Outlook again.
According to users, you can fix the problem with Outlook simply by deleting the Outlook AppData folder.
If Outlook manages to start, all the deleted files will be recreated and the problem should be completely resolved.
This method can help if Outlook won’t open attachments, so we encourage you to give it a try.
15.2 Delete the outlook.xml file
- Press Windows key + R and enter %appdata%. Press Enter.
- Go to the Microsoft Outlook folder, locate outlook.xml file and delete it.
- Start Outlook again.
16. Check if you have permissions to access your PST file
- Locate your PST file, right-click it and choose Properties from the menu.
- Go to the Security tab and check if your username is available in the Group or user names section. If it’s not, click the Edit button.
- Now click the Add button to add a new user.
- In the Enter the object names to select field, enter your user name, and click Check Names.
- If your user name is valid, click OK to add it.
- Select your user name from the Group or user names section and click on Full Control in the Allow column.
- Click Apply and OK to save the changes.
Outlook holds all your information in a PST file, but if you don’t have the necessary permissions to access this file, you might encounter certain errors.
In the worst-case scenario, Outlook won’t be able to open on your PC.
Fortunately, you can fix this problem simply by changing your security permissions. This is a simple procedure and you can do it by following the steps above.
After gaining full control over your PST file, you should be able to start Outlook without any problems.
17. Run the sfc /scannow command
- Type cmd in Windows search and click on Run as administrator.
- When Command Prompt opens, enter the following command and press Enter:
- After the scan is completed, check if the problem with Outlook is resolved.
If your files are corrupted, you might not be able to start Outlook at all, but fortunately, you fix this problem by performing an SFC scan.
This is a simple command that will scan and repair your system, and you can perform it by following the steps above.
18. Delete the registry key
- Press Windows key + R and enter regedit.
- In the left pane, navigate to the following path and expand it:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem
- Select Profiles key, right-click it, and choose Delete.
- After doing that, restart your PC and check if the problem is resolved.
You can sometimes fix the problem with Outlook simply by deleting a specific key from your registry.
Before making any changes to the registry, we strongly advise you to back up your registry in case anything goes wrong.
19. Remove the VPN software
VPN tools are useful if you want to protect your privacy while surfing the Internet, but VPN tools can interfere with Outlook and cause this and many other problems to appear.
Users are suggesting disabling or removing your VPN software and checking if that fixes the problem.
Another suggestion from one of our readers is to end the Outlook process from the Background processes section in Task Manager. It won’t hurt to try that out to fix this issue.
20. Reinstall Outlook
- Press Windows key + X and select Apps and Features.
- Select Microsoft Office or Outlook and click on Modify.
- Now choose the Repair option.
Alternatively, you can just reinstall the software and check if that solves the problem. If Outlook won’t open in Safe Mode, then it’s possible that your installation is damaged, so be sure to try this solution.
What to do if Outlook won’t open on Windows 11?
If you’re having this issue on Windows 11, you’re in luck, because all solutions from this guide can be applied to the latest version of Windows.
Since the two versions of Windows are quite similar in terms of functionality, most of our solutions will work on both of them.
Do keep in mind that some solutions might have to be slightly altered due to interface changes on the latest version.
Not being able to start Outlook can be a big problem, especially if you use Outlook as your default email client, but you can easily fix this problem by using one of our solutions.
In case the problem is still there, visit our Something went wrong in Outlook guide for more solutions.
What solution did you use to fix this problem? Let us know in the comments section below.
Frequently Asked Questions
Running an outdated Outlook version or a computer that hasn’t been restarted in a long time usually causes grayed out attachment issues. If the PC is stuck, use this quick guide.
To get to those emails that you want to export, try to repair corrupted files with the help of this handy procedure and see if Outlook finally opens.
Diagnosing why your Outlook won’t open isn’t an easy task since there are multiple scenarios to consider. Therefore, we can only encourage you to use this dedicated guide.