Hi again Gunasekar,

I just did Cntl Alt delete and saw that both Classic Outlook and the new Outlook were both running, I stopped both processes and now Classic Outlook opens and I can send/receive emails once again :-)

Thanks again for your willingness to help others.

Top answer
1 of 4
35

Hi again Gunasekar,

I just did Cntl Alt delete and saw that both Classic Outlook and the new Outlook were both running, I stopped both processes and now Classic Outlook opens and I can send/receive emails once again :-)

Thanks again for your willingness to help others.

2 of 4
7

Hello LesleyRitchie1! I'm Gunasekar and I'd be happy to help you with your question.

I understand that you are experiencing an issue opening the Outlook Program on your PC. You could try the following suggestions if you are having trouble opening the Outlook application on your Windows 10 Operating system.

  1. Check if the Program works in safe mode or not.

Start-> type; Outlook.exe /safe (Note the space in the command)

When you run Outlook in safe mode, it bypasses functionality and settings such as alternative startup location, changed toolbars, startup folders used by Outlook, Outlook add-ins, and most COM add-ins. While add-ins can enhance your experience, they can occasionally interfere, or conflict with Outlook.

If the issue persists,

  1. Repair Office applications.

a. Right-click the Start button Windows Start button (lower-left corner), select Settings, and click > Apps. b. Select the Microsoft Office product you want to repair, and select Modify. c. Follow the instructions on the screen to complete the repair. (Select Online repair)

  1. If the issue continues, Create a new Outlook profile.

a. Open control panel. b. Change the category to small or large icons. c. Click Mail (Microsoft Outlook). d. In the window, click Show Profile. e. Click Add, name it (whatever name you want to) f. Enter your e-mail address and click next. g. Your new Outlook Profile has been created.

When starting Outlook, select the new profile created and sign in with your account.

I hope this information helps. If you have any questions, please let me know and I’ll be glad to assist you further.

Best regards,

Gunasekar N

🌐
Microsoft Support
support.microsoft.com › en-us › office › i-can-t-start-microsoft-outlook-or-receive-the-error-cannot-start-microsoft-outlook-cannot-open-the-outlook-window-d1f69da6-b333-4650-97bf-4d77bd7abb85
I can’t start Microsoft Outlook or receive the error “Cannot start Microsoft Outlook. Cannot open the Outlook Window” - Microsoft Support
You need to be on the same Windows PC as classic Outlook to run the troubleshooter. If the troubleshooter can't fix your issue, or if you'd like to fix it yourself, see the next section. Sometimes add-ins can conflict with Outlook. Starting Outlook in safe mode, which starts Outlook without add-ins loaded, can tell you if an add-in is the source of the problem. Note: If you enabled an ABBYY FineReader add-in, an outdated version of the software might cause an Outlook startup error.
🌐
Microsoft Support
support.microsoft.com › en-us › office › fixes-or-workarounds-for-recent-issues-in-classic-outlook-for-windows-ecf61305-f84f-4e13-bb73-95a214ac1230
Fixes or workarounds for recent issues in classic Outlook for Windows - Microsoft Support
​​​​​​​[FIXED] Classic Outlook error when sending from Outlook.com "You do not have permission to send on behalf of the specified user." ​​​​​​​[FIXED] Error opening classic Outlook: "Cannot start Microsoft Outlook. Cannot open the Outlook window.
🌐
Reddit
reddit.com › r/sysadmin › what's going on with outlook classic? is microsoft making changes?
r/sysadmin on Reddit: What's going on with Outlook Classic? Is Microsoft making changes?
April 24, 2025 -

Hi,

We're seeing sporadic issues reported by users across different tenants (all using M365 and Outlook Classic), where they can't launch Outlook Classic anymore. The error message is: "Information Store could not be opened."

Creating a new profile doesn't help either, as no connection to the server can be established.

In some cases, the issue magically resolves the next day without any changes being made. The same problem is described here:

https://answers.microsoft.com/en-us/outlook_com/forum/all/outlook-classic-will-not-connect-to-o365-account/e157ece2-b7f0-493e-bd39-39722060ac8a

Unfortunately, we still haven't found a proper solution. Is anyone else experiencing this and has found a fix?

🌐
Microsoft Support
support.microsoft.com › en-us › office › classic-outlook-not-responding-stuck-at-processing-stopped-working-or-freezes-5c313d04-64af-4441-82d2-44e5a43eee5a
Classic Outlook not responding, stuck at "Processing," stopped working, or freezes - Microsoft Support
Note: These steps are not applicable to new Outlook for Windows. Check to see if the new Outlook toggle is turned on or off. If it's on, please go to Troubleshooting Outlook issues. If Outlook stops responding at a screen that says "Processing," you can close Outlook, start it in safe mode, ...
🌐
Reddit
reddit.com › r/sysadmin › it has started, user opened outlook and it is now new outlook, and outlook classic is no longer installed.
r/sysadmin on Reddit: It has started, user opened Outlook and it is now New Outlook, and Outlook Classic is no longer installed.
January 23, 2025 -

Not able to toggle back because Outlook Classic was uninstalled.
After some research, we were able to reinstall Outlook Classic using this link:
https://apps.microsoft.com/detail/xp9mhd8pgh9n47?hl=en-US&gl=US

Also created a GPO and set up this registry key:
reg.exe ADD "HKCU\SOFTWARE\Policies\Microsoft\Office\16.0\Outlook\Preferences" /v NewOutlookMigrationUserSetting /t REG_DWORD /d 0 /f

https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/control-install

Also ran this on the user's PC:
reg.exe ADD "HKCU\SOFTWARE\Microsoft\Office\16.0\Outlook\Preferences" /v UseNewOutlook /t REG_DWORD /d 0 /f

🌐
Eleven Forum
elevenforum.com › windows support forums › office and productivity
I am trying to get Outlook Classic to open | Windows 11 Forum
July 2, 2025 - Hi i have followed the above articles to try and get outlook classis to open with no success. the repair the outlook data file did not work so i had the idea just to delete the data file and when outlook next started it created a new one and now the classic version is now opening just fine
🌐
Microsoft Support
support.microsoft.com › en-us › office › install-or-reinstall-classic-outlook-on-a-windows-pc-5c94902b-31a5-4274-abb0-b07f4661edf5
Install or reinstall classic Outlook on a Windows PC - Microsoft Support
If you recently bought a new Windows device, you might not be able to find classic Outlook, or the icon appears, but when you try to open it, you might get an error that says, We couldn't verify and install this because it is not available in the Microsoft Store.
Find elsewhere
Top answer
1 of 4
35

Hi again Gunasekar,

I just did Cntl Alt delete and saw that both Classic Outlook and the new Outlook were both running, I stopped both processes and now Classic Outlook opens and I can send/receive emails once again :-)

Thanks again for your willingness to help others.

2 of 4
7

Hello LesleyRitchie1! I'm Gunasekar and I'd be happy to help you with your question.

I understand that you are experiencing an issue opening the Outlook Program on your PC. You could try the following suggestions if you are having trouble opening the Outlook application on your Windows 10 Operating system.

  1. Check if the Program works in safe mode or not.

Start-> type; Outlook.exe /safe (Note the space in the command)

When you run Outlook in safe mode, it bypasses functionality and settings such as alternative startup location, changed toolbars, startup folders used by Outlook, Outlook add-ins, and most COM add-ins. While add-ins can enhance your experience, they can occasionally interfere, or conflict with Outlook.

If the issue persists,

  1. Repair Office applications.

a. Right-click the Start button Windows Start button (lower-left corner), select Settings, and click > Apps. b. Select the Microsoft Office product you want to repair, and select Modify. c. Follow the instructions on the screen to complete the repair. (Select Online repair)

  1. If the issue continues, Create a new Outlook profile.

a. Open control panel. b. Change the category to small or large icons. c. Click Mail (Microsoft Outlook). d. In the window, click Show Profile. e. Click Add, name it (whatever name you want to) f. Enter your e-mail address and click next. g. Your new Outlook Profile has been created.

When starting Outlook, select the new profile created and sign in with your account.

I hope this information helps. If you have any questions, please let me know and I’ll be glad to assist you further.

Best regards,

Gunasekar N

Top answer
1 of 2
1

Dear michel coilbeau,

Welcome to Microsoft Community.

According to your description, you can't open Classic Outlook. Don't worry, you can try my suggestions below to troubleshoot this problem, I hope my suggestions can help you.

  1. You can try restarting your computer and check to see if Classic Outlook opens properly.
  2. You can enter the safe mode of Outlook and check whether classic Outlook can be opened normally.

  1. You can go to Control Panel\User Accounts, select Mail, then select Show Profiles, try removing the current profile, or create a new profile and reset the mailbox to check that you can open Classic Outlook properly.

  1. If none of the above suggestions help you open Classic Outlook properly. I can only recommend that you contact Microsoft's online support staff to ask for help, you can click on this link and follow the step-by-step instructions below to contact them. Contact - Microsoft Support

1). First, enter your question in the search, then click "Sign up to contact support" at the bottom of the page.

2). Currently logged in to another valid Microsoft account. (Please make sure you sign in with your personal Microsoft account, not your work and school account, or you won't see option 3、4、5.)

3). Under "Products & Services", select "Other Products".

4). Under Categories, select Manage my Subscription and then click Confirm.

5). Click Chat with Support Agent in web browser.

Please contact Microsoft online support staff during business hours.

I hope this information has been helpful. If you have any questions, please let me know and I will be happy to help you further.

Have a good day.

Best Regards, 

Jim - MSFT | Microsoft Community Support Specialist

2 of 2
0

I tried many times to download and install but it never would show up as the outlook.exe file, folder, etc. use this website You can't open classic Outlook on a new Windows PC - Microsoft Support

🌐
YouTube
youtube.com › watch
How to fix Outlook when it won't start - YouTube
Outlook doesn't open when you click on it? In this video I'll show you how to get Outlook running again on your Windows computer.00:00 Intro00:32 Use Task Ma...
Published   July 26, 2024
Views   3K
🌐
JustAnswer
justanswer.com › microsoft-office › rwcgk-classic-version-outlook-will-not-open-getting.html
Fix Classic Outlook Not Opening on Laptop - FAQ
May 3, 2025 - If Outlook Classic won’t open on your laptop, first try running it in Safe Mode by holding Ctrl while launching. Check for corrupted add-ins via File > Options > Add-ins and disable suspicious ones.
🌐
Microsoft Support
support.microsoft.com › en-us › office › classic-outlook-crashes-opening-or-starting-a-new-email-1b413573-7dfc-4147-9c53-c2f1183b89b8
Classic Outlook crashes opening or starting a new email - Microsoft Support
This issue occurs because Outlook cannot open the Forms Library. This issue can occur for Outlook on all Microsoft 365 Office channels. The emerging cases for this issue are on virtual desktop infrastructure (VDI). This issue started occurring in all production channels and versions of classic Outlook with the June 10, 2025, public updates, Release notes for Microsoft Office security updates.
🌐
Microsoft Support
support.microsoft.com › en-us › office › go-back-to-classic-outlook-button-not-working-correctly-in-new-outlook-395a8f53-94a1-44bb-9a9d-a8818fe6f4b5
Go back to classic Outlook button not working correctly in new Outlook - Microsoft Support
The application just closes, and classic Outlook is not installed. ... The Outlook team has fixed this issue. ... If you are experiencing this problem, reference the store install link included in this article, You can't open classic Outlook on a new Windows PC.
Top answer
1 of 2
1

Dear michel coilbeau,

Welcome to Microsoft Community.

According to your description, you can't open Classic Outlook. Don't worry, you can try my suggestions below to troubleshoot this problem, I hope my suggestions can help you.

  1. You can try restarting your computer and check to see if Classic Outlook opens properly.
  2. You can enter the safe mode of Outlook and check whether classic Outlook can be opened normally.

  1. You can go to Control Panel\User Accounts, select Mail, then select Show Profiles, try removing the current profile, or create a new profile and reset the mailbox to check that you can open Classic Outlook properly.

  1. If none of the above suggestions help you open Classic Outlook properly. I can only recommend that you contact Microsoft's online support staff to ask for help, you can click on this link and follow the step-by-step instructions below to contact them. Contact - Microsoft Support

1). First, enter your question in the search, then click "Sign up to contact support" at the bottom of the page.

2). Currently logged in to another valid Microsoft account. (Please make sure you sign in with your personal Microsoft account, not your work and school account, or you won't see option 3、4、5.)

3). Under "Products & Services", select "Other Products".

4). Under Categories, select Manage my Subscription and then click Confirm.

5). Click Chat with Support Agent in web browser.

Please contact Microsoft online support staff during business hours.

I hope this information has been helpful. If you have any questions, please let me know and I will be happy to help you further.

Have a good day.

Best Regards, 

Jim - MSFT | Microsoft Community Support Specialist

2 of 2
0

I tried many times to download and install but it never would show up as the outlook.exe file, folder, etc. use this website You can't open classic Outlook on a new Windows PC - Microsoft Support