Use Multiple Windows in New Outlook After Switching From Classic Outlook

In Classic Outlook, you could open multiple separate windows for the same mailbox by double-clicking a folder or using the File > Open & Export > Open Outlook Data File method. After switching to New Outlook, this behavior changes. The new version is designed as a single-window app, which can feel restrictive if you rely on side-by-side views of your inbox and calendar or need two folders open at once. This article explains the differences, how to work around the limitation, and the best ways to regain multi-window functionality in New Outlook.

Why New Outlook Removes Multiple Windows

New Outlook is built on a web-based framework that runs inside a single desktop process. Unlike Classic Outlook, which uses separate window handles for each folder, New Outlook treats the entire application as one window. This design improves memory usage and sync performance, but it eliminates the ability to drag a folder tab out into its own window.

The main trigger for this change is the underlying architecture. Classic Outlook uses MAPI and COM components that support multiple windows natively. New Outlook uses the same rendering engine as Outlook on the web, which is designed for a single browser-like window. Microsoft has not added a toggle to restore Classic behavior, so users must adapt to the new workflow.

What You Lose When Switching

In Classic Outlook, you could open your inbox and calendar in separate windows, then arrange them on two monitors. You could also open a second window to view a different mailbox without closing the first. New Outlook does not support these actions. When you click a folder, it replaces the current view within the same window. The only items that open in separate windows are individual messages, meeting requests, and attachments.

How to Open Separate Windows in New Outlook

While New Outlook does not allow you to open a folder in a new window, it does support separate windows for composing items and viewing individual messages. Use the methods below to get as close as possible to the Classic multi-window experience.

1. Open a message in its own window
   Double-click any message in your inbox. The message opens in a separate window. You can move this window to a second monitor or resize it independently from the main Outlook window. To return to the inbox, close the message window or click the back arrow.
2. Compose a new email or meeting in a separate window
   Press Ctrl+Shift+M to open a new email message window. Press Ctrl+Shift+Q for a new meeting request. These windows are independent of the main Outlook window. You can compose while still viewing your calendar or inbox in the background.
3. Pop out a meeting or appointment from the calendar
   Open the calendar view. Double-click an event. The event detail window opens separately. You can edit details or view the event side by side with your inbox.
4. Use the pop-out button for reading pane items
   When reading a message in the reading pane, click the pop-out icon located in the top-right corner of the message header. The message moves to its own window. This is faster than double-clicking the message in the list.
5. Open a second instance of New Outlook
   Right-click the Outlook icon on the taskbar and select Outlook. If New Outlook is already running, this opens a second instance of the app. You can log into the same account or a different one. The second instance runs in its own window. This allows you to view two folders at the same time, though each instance loads its own copy of the mailbox.

Limitations of the Second Instance Method

Opening a second instance of New Outlook consumes more system memory because each instance runs its own process. On a computer with 8 GB of RAM or less, this may cause slowdowns. Also, changes made in one instance may take a few seconds to appear in the other. This method works best for temporary tasks like comparing two folders during a move or copy operation.

Common Mistakes and Workarounds That Do Not Work

Dragging a folder tab to create a new window

In Classic Outlook, you could click and drag a folder tab away from the main window to create a separate window. In New Outlook, folder tabs are not draggable. If you try to drag a folder name, Outlook selects the text or does nothing. There is no hidden setting to re-enable this behavior.

Using the File menu to open a new window

Classic Outlook had a File > Open & Export > Open Outlook Data File command that opened a new window with the selected PST file. New Outlook does not support PST files. The File menu in New Outlook contains only Account, Settings, and Exit options. You cannot open a new window from the File menu.

Pressing Ctrl+N for a new window

In many Windows applications, Ctrl+N opens a new instance of the window. In New Outlook, Ctrl+N opens a new email message in a separate window, not a new main Outlook window. This is useful for composing but does not give you a second folder view.

New Outlook vs Classic Outlook: Multi-Window Features

Item	New Outlook	Classic Outlook
Open folder in new window	Not supported	Right-click folder > Open in new window
Open message in separate window	Double-click message or pop-out button	Double-click message
Compose email in separate window	Ctrl+Shift+M	Ctrl+Shift+M
Open calendar in new window	Not supported	Right-click calendar > Open in new window
Run multiple instances	Launch Outlook from Start menu while running	Launch Outlook from Start menu while running
Drag folder tab to create new window	Not supported	Supported

New Outlook gains a cleaner interface and faster sync, but loses the ability to rearrange folder windows freely. Users who need multiple folder views should consider the second instance method or keep Classic Outlook installed for advanced scenarios.

You can now open individual messages and compose items in separate windows in New Outlook. For folder-level multi-window use, launch a second instance from the Start menu. If you frequently need two folder views side by side, consider adding a second monitor and using the pop-out message windows to fill the extra screen space. The Ctrl+Shift+M shortcut remains the fastest way to start composing without closing your current view.