Why this happens

Outlook (classic) is the traditional desktop version that comes with Microsoft Office/Microsoft 365.
New Outlook is a separate Windows app (often installed from the Microsoft Store). Even if you use
Outlook Classic every day, Windows can still open calendar links using New Outlook if the default app for
.ICS files (iCalendar invites) changes.

Step 1: Make Outlook (classic) the default for .ICS links

This step fixes the common scenario: you click “Add to calendar,” Windows opens New Outlook, and you want Classic.

1. Open Settings in Windows.
2. Go to Apps → Default apps.
3. Scroll to (or search for) Choose defaults by file type.
4. Find .ics and set it to Outlook (classic).
5. If your system shows other calendar-related entries, also check and set them to Outlook (classic) where appropriate:
   • .vcs (if present)
   • webcal (if present)
6. Test it: download/open any .ics invite and confirm it opens in Classic Outlook.

Pro tip: Microsoft/Windows updates can occasionally reset defaults. If the issue returns, re-check the .ics association first.

Step 2: Uninstall the New Outlook app (keep Classic)

If you want New Outlook removed entirely (and not just “not the default”), uninstall it as an app.

1. Open Settings → Apps → Installed apps.
2. Search for Outlook (new) or Outlook for Windows.
3. Click the three dots (⋯) → Uninstall.
4. Restart your PC.
5. Confirm Outlook (classic) still opens normally (it should).

Not seeing New Outlook in Installed apps? That’s common on some workstations—use the PowerShell method below.

Step 3: Remove New Outlook with PowerShell (when it won’t uninstall)

New Outlook is often installed as an AppX package. If it doesn’t show up in the normal uninstall list, you can remove it with PowerShell.
(You may need admin rights on a work computer.)

Remove for your Windows user account

Get-AppxPackage Microsoft.OutlookForWindows | Remove-AppxPackage

Remove for all users (admin)

Get-AppxPackage -AllUsers Microsoft.OutlookForWindows | Remove-AppxPackage -AllUsers

Remove the provisioned package (prevents it from reappearing for new profiles)

Get-AppxProvisionedPackage -Online |
  Where-Object {$_.DisplayName -eq "Microsoft.OutlookForWindows"} |
  Remove-AppxProvisionedPackage -Online

After removal, re-check Settings → Apps → Default apps to ensure .ics still points to Outlook (classic).

Optional: Prevent New Outlook from reinstalling

On some systems, Windows or Microsoft 365 update mechanisms can attempt to reintroduce New Outlook. Microsoft documents an approach that uses
a Windows Update Orchestrator registry value to block the “MS_Outlook” OOBE updater.
This is typically used by IT/admins.

Registry path (admin)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler_Oobe

String value

• Name: BlockedOobeUpdaters
• Type: REG_SZ
• Value: [“MS_Outlook”]

Note: If your computer is managed by your organization, your IT team may already control this behavior via policy.

Optional: Hide the “Try the new Outlook” toggle in Classic Outlook

If users keep switching accidentally, Microsoft documents a registry setting that can hide the “Try the new Outlook” toggle in Classic Outlook.
(Useful in business environments.)

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options\General]
"HideNewOutlookToggle"=dword:00000001

Some organizations enforce this via policy under:
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Options\General

Troubleshooting

“Add to calendar” opens New Outlook even after I changed defaults

• Re-check that .ics is set to Outlook (classic) (this is the #1 culprit).
• Restart Windows after changing defaults (sometimes required).
• Try downloading the .ics file first, then opening it from File Explorer.

I removed New Outlook, but it came back

• This can happen on managed PCs where updates/policies reinstall it.
• Use the prevent reinstall option (admin/IT) or ask your IT team to block it.

I don’t have admin access (work computer)

• You can usually still do Step 1 (default app association), but uninstall/removal may require IT.
• Send IT the PowerShell/registry snippets from this page as a request.

FAQ

Will uninstalling New Outlook remove Outlook Classic?

No. Outlook Classic is part of Office/Microsoft 365 (Win32). New Outlook is a separate app. Removing New Outlook should not uninstall Classic Outlook.

Why doesn’t New Outlook show in Control Panel “Programs and Features”?

Because New Outlook is often installed as a Windows Store/AppX app, which appears under Settings → Apps → Installed apps (or requires PowerShell removal).

What should open calendar invite files?

For Classic Outlook users, the most important association is .ics → Outlook (classic).