Outlook Window Position Not Saving After Restart: How to Reset Window State

You close Outlook and expect it to reopen in the same position and size. Instead, it appears in a different spot or as a small window. This happens because Outlook’s window state data becomes corrupted or is blocked from saving. This article explains the root cause and provides steps to reset the window layout so Outlook remembers your preferences.

Why Outlook Forgets Your Window Layout

Outlook stores your window position, size, and pane layout in a small data file. The primary file is called Extend.dat. This file holds profile-specific UI settings. When you close Outlook normally, it writes the current window state to this file. If the file becomes corrupted or is set to read-only, the save operation fails. The next time Outlook starts, it uses default window coordinates because it cannot read the saved data.

Another common cause is interference from other programs. Display scaling changes in Windows, multiple monitor setups, or certain graphics driver utilities can conflict with how Outlook measures screen coordinates. Some Outlook add-ins may also hook into the window closing process and inadvertently block the settings from being written to disk. Running Outlook in Safe Mode helps diagnose this.

How the Extend.dat File Works

The Extend.dat file is located in a hidden system folder tied to your user profile. It is not a configuration file you can edit. Outlook reads from it during startup and writes to it upon a clean exit. Corruption often occurs after an unexpected shutdown, like a system crash or force-quitting Outlook. A corrupted file may not cause other errors, leading to the isolated issue of a forgotten window position.

Steps to Reset the Outlook Window State

Follow these methods in order. Start with the simple reset and proceed to more direct file operations if the problem continues.

Method 1: Manually Reset the Window Layout

1. Reposition and resize the Outlook window
   Drag the Outlook window to your preferred location on the screen. Drag the corners to set your desired size. Do not maximize the window.
2. Adjust the Navigation Pane width
   Move your cursor to the right edge of the Navigation Pane, the left column with your folders. Click and drag the divider slightly to the left or right. This action often triggers a UI refresh.
3. Close Outlook properly
   Go to File > Exit. Do not just click the X in the window corner, as this may only hide Outlook to the system tray if Quick Launch is enabled.
4. Restart Outlook
   Open Outlook again. Check if the window opens in the position and size you just set.

Method 2: Delete the Corrupted Settings File

1. Close Outlook completely
   Right-click the Outlook icon in the system tray and select Exit. Verify it is not running in Task Manager.
2. Open the Run dialog
   Press the Windows key + R on your keyboard.
3. Enter the file path
   Type or paste %localappdata%\Microsoft\Outlook into the Run box and press Enter. This opens a File Explorer window.
4. Find and delete the file
   Look for a file named Extend.dat. Select it and press Delete on your keyboard. If you see a file named Extend.dat.bak, you can delete that as well.
5. Restart Outlook
   Open Outlook. It will create a new, clean Extend.dat file. Set your window position and size, then close Outlook via File > Exit to save the new settings.

If the Window Position Still Won’t Save

Outlook Opens Minimized or Off-Screen

This can happen if Windows records coordinates for a monitor that is no longer connected. With Outlook closed, right-click its taskbar icon and select Move. Press any arrow key on your keyboard. Then, use your mouse to drag the window outline back onto your visible screen. Close and restart Outlook to save the new position.

Add-ins Blocking Settings Save

1. Start Outlook in Safe Mode
   Press Windows key + R, type outlook.exe /safe, and press Enter.
2. Set your window layout
   Position and size the window as desired in Safe Mode.
3. Exit and restart normally
   Close Outlook and open it normally. If the position is saved now, an add-in is the cause. Disable add-ins via File > Options > Add-ins and re-enable them one by one to find the culprit.

Windows or Graphics Driver Interference

Ensure your Windows display drivers are updated. If you use display management software from NVIDIA, AMD, or Intel, try temporarily disabling its features. Also, check that your Windows display scaling is set to 100%. Go to Settings > System > Display and look at the Scale setting.

Manual Reset vs. File Deletion: Comparison

Item	Manual Window Reset	Delete Extend.dat File
Primary Action	Drag panes and resize window	Delete the corrupted settings file
Complexity	Simple, no file navigation	Requires finding a hidden system file
Best For	Minor corruption or recent layout change	Persistent failure where manual reset does not work
Risk Level	None	Low; Outlook recreates the file automatically
Other Settings Affected	None	Resets other UI pane widths and customizations

You can now make Outlook remember your preferred window position. Start by simply adjusting the Navigation Pane and closing Outlook properly. If the issue returns, use the Extend.dat deletion method for a more complete reset. For advanced control, use the Windows shortcut Win + Left/Right Arrow to snap the Outlook window to a screen edge, which can help establish a consistent starting position.