How to Restart Outlook on Windows and Mac (5 Methods)

Outlook freezing on a draft you spent ten minutes writing is the worst kind of bug. A clean restart fixes most of these stalls without touching your emails, because Outlook stores messages in PST or OST data files that stay safe even when the app crashes. We walked through five restart methods that work across Outlook for Microsoft 365, Outlook 2021, and the older Outlook 2016 build many offices still run.

#Why Does Outlook Stop Responding?

Most freezes trace back to four causes. Naming yours saves time.

The most common trigger we hit in testing was an add-in conflict. That usually happens after a Windows update or a Teams upgrade pushes a refreshed COM add-in that doesn’t play nicely with the installed Outlook build.

The second culprit is mailbox bloat. Microsoft states that the default PST and OST size limit is 50 GB on Outlook 2010 and later, per its Outlook data file size limit guide. In practice Outlook noticeably slows once the OST file passes about 30 GB, and a single hung sync request can freeze the whole window.

Other triggers include corrupted profile registry keys, a stuck navigation pane, and conflicts with antivirus software scanning every incoming message in real time. According to Microsoft’s Outlook hangs or freezes guide, most of these stalls clear after a forced close and a clean relaunch of the app.

#How to Restart Outlook on Windows in 4 Steps

This is the fastest fix on Windows 10 and Windows 11. We tested it on Outlook for Microsoft 365 build 17328.20146 running on Windows 11 23H2, and the full sequence finished quickly.

1. Press Ctrl+Shift+Esc to open Task Manager. (Ctrl+Alt+Delete also works; then click Task Manager.)
2. In the Processes tab, scroll to Microsoft Outlook or outlook.exe. If you see multiple Outlook entries, they’re usually background sync threads, which is normal.
3. Click the Outlook entry once, then click End Task at the bottom right. Confirm if Windows asks.
4. Reopen Outlook from the Start menu or the taskbar shortcut. The first launch after a forced end can take 10 to 15 seconds while OST files reindex.

Done. That clears almost every transient freeze.

If Outlook still won’t open after step 4, try the navigation pane reset. Press Win+R to open the Run dialog, type outlook.exe /resetnavpane, and hit Enter. That’s Microsoft’s standard fix when Outlook crashes on launch with a navigation pane error.

We used the reset last month on a colleague’s machine after an Outlook 2021 update broke her custom folder favorites. The relaunch worked on the first try and kept all of her saved views.

If your Outlook loading profile screen freezes before the inbox loads, that’s a separate fix.

#How to Restart Outlook on Mac with Force Quit

Outlook for Mac handles restarts differently because macOS doesn’t have a Run dialog. In our testing on a 2023 MacBook Air running macOS Sonoma 14.4, Force Quit finished cleanly across five consecutive attempts. The whole sequence is quick once you’re used to the keyboard shortcut, and it works on both the new unified Outlook and the legacy build still installed on many older Macs.

1. Press Cmd+Option+Esc to open the Force Quit Applications window.
2. Select Microsoft Outlook from the app list.
3. Click Force Quit and confirm in the popup.
4. Reopen Outlook from Launchpad, the Dock, or Spotlight (Cmd+Space, then type Outlook).

If Outlook for Mac refuses to quit, open Activity Monitor (Spotlight, then type Activity Monitor), select Microsoft Outlook, click the X button in the toolbar, and choose Force Quit. That routes around a hung modal dialog the Force Quit Applications window sometimes can’t see.

The new Outlook for Mac syncs less aggressively than the legacy version, so the relaunch typically shows your inbox within 5 seconds. If your Mac is taking longer, check whether iCloud Mail sync is also running, because both processes hitting the mail database at once is a known slowdown.

#How to Restart Outlook in Safe Mode and Disable Add-Ins?

Safe Mode strips Outlook back to the bare client with zero add-ins loaded, no startup macros, and a barebones toolbar layout. Microsoft’s Office safe mode documentation confirms that this is the right diagnostic step when Outlook crashes on startup, freezes inside specific folders, or pops error dialogs the moment you click a meeting invite. Think of it as Outlook with every optional moving part disabled, so any bug that disappears must be coming from one of those parts.

Here’s how to start Outlook in Safe Mode on Windows.

1. Close Outlook completely. Check Task Manager to confirm no outlook.exe process is running.
2. Press Win+R, type outlook.exe /safe, and hit Enter. The space before /safe matters.
3. If Outlook prompts for a profile, pick the one you normally use and click OK.
4. When Outlook opens, the title bar will say Microsoft Outlook (Safe Mode).

Now check whether the bug you’re chasing is gone. If Outlook works fine in Safe Mode but breaks in normal mode, the cause is an add-in. To find the culprit, go to File > Options > Add-Ins, click the Manage dropdown at the bottom, choose COM Add-Ins, and click Go. Uncheck every add-in, click OK, then restart Outlook normally.

If Outlook is stable, re-enable add-ins one at a time. After each re-enable, restart Outlook and check again. The add-in that brings the crash back is your problem.

Common offenders we saw in 2024 and 2025 were the Teams Meeting add-in and older Adobe Acrobat PDFMaker builds. Both have updates that fix the conflict, and patching to the latest version usually solves the freeze without disabling the add-in entirely.

If your specific issue is the password prompt looping every few minutes, the Outlook keeps asking for password fix covers credential cache resets that Safe Mode alone can’t solve.

#Run Microsoft Support and Recovery Assistant

When a clean restart, a /resetnavpane reset, and Safe Mode all fail, the problem is deeper than a transient hang.

Microsoft’s Support and Recovery Assistant documentation recommends running SaRA as the first automated diagnostic when Outlook errors persist after a restart. Download the tool from the official Microsoft page, run it, choose Outlook from the app list, then pick the scenario that matches your problem.

In our testing on the same Windows 11 box, the “Outlook keeps crashing” scenario took several minutes to scan and produced a one-page report pointing at a stale Teams add-in registry entry. That kind of targeted diagnosis is hard to reach by hand.

#Repair Your Outlook PST or OST File or Create a New Profile

A corrupted data file or a broken profile causes the worst Outlook crashes, because no restart touches the underlying state. Two repairs handle most of these cases.

#Repair Your PST or OST File

Microsoft’s Inbox Repair Tool guide confirms that scanpst.exe can repair corruption inside PST files; OST files repair by deleting and resyncing.

To find scanpst.exe, search your C: drive for it. The typical path is C:\Program Files\Microsoft Office\root\Office16. Close Outlook, run scanpst.exe, browse to your PST file (usually under C:\Users\[you]\Documents\Outlook Files), and click Start. We ran scanpst on a 5 GB PST recently, and the repair finished in a reasonable amount of time.

If Outlook keeps crashing even after a clean scanpst pass, the next step is usually a fresh Outlook profile rather than another repair attempt.

#Create a New Outlook Profile

A corrupted Windows profile registry entry causes Outlook to crash even after a fresh PST file repair, because the profile holds the account configuration, the OST file pointer, the navigation pane layout, and a bundle of settings keys under HKEY_CURRENT_USER\Software\Microsoft\Office. Creating a new profile bypasses the broken one without removing your account credentials, and Outlook will rebuild the OST file from your server on the first sync.

1. Close Outlook. Press Win+R, type control mlcfg32.cpl, and hit Enter. (Newer Windows 11 builds may need control then click Mail manually.)
2. Click Show Profiles, then Add.
3. Type a new profile name. Any name works; we use Outlook-Fresh because it makes the new entry obvious in the dropdown.
4. Enter your email address and password when prompted. Outlook auto-configures most accounts.
5. Set the new profile as default under “Always use this profile” and click OK.

Open Outlook, let it finish the first sync, and check whether the original bug is gone. If yes, the old profile was corrupted, and you can delete it from the same Show Profiles screen.

Outlook also throws fits when it can’t reach the mail server. The Outlook disconnected fix covers connectivity issues that look like crashes but are really network problems.

#Bottom Line

Start with the Task Manager restart; it resolves most single-session freezes in under a minute. If the same crash returns within an hour, jump straight to Safe Mode with outlook.exe /safe and disable add-ins one by one. Save SaRA and PST repair for stubborn cases where Outlook fails to launch at all. If your view suddenly changed instead of crashing, use the view reset command, not a restart.

#Frequently Asked Questions