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Outlook calendar issues after Windows 11 upgrade

Maria Waddell 0 Reputation points
2026-05-29T19:16:49.9833333+00:00

I reluctantly upgraded to Windows 11 in December when a notice went out that unless done so, it would not be supported. I was afraid this was going to happen. This happens every time there is a major MS upgrade. I set an appointment in my Outlook calendar for example, 8am. For some reason, even though I schedule for 8 am, there are some appointments that appear on there as 3 or 4 am time settings-although the calendar event still scheduled for 8am, and even though I am on the New York Time zone (the Geek Squad fixed that on one appointment but it didn't help). I don't get reminders about all the appointments now even though I set them for either the day before or the week before. I have been to the Geek Squad 3 times within the last 2 weeks and each time they "fix" it along other upgrade issues. Still not fixed. I have become late paying my bills because of lack of reminders. I have undue stress over this whole ordeal, not to mention the 22,000 + emails all dumped into the Archive folder. (I didn't even know there was an Archive folder till this upgrade). I have emails in subfolders that don't belong there. I cannot find anything. I have a string of empty subfolders. I am so frustrated that I am deleting thousands of emails, all research for the several projects I work on. When I create a new Outlook folder within my Inbox, it goes above it, not within it. I have a small business and instead of spending my time marketing my business, I am cleaning up the mess from the Windows 11 upgrade. Microsoft which is costing me thousands of dollars in lack of work. I am considering strongly to go with a MAC because everyone I know doesn't have these problems. And MS is not available to help me with this mess.

Outlook | Windows | Classic Outlook for Windows | For home
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  1. AI answer

    2026-05-29T19:17:12.7066667+00:00

    The issues described are consistent with known Outlook problems after Windows updates and with the transition to newer Outlook experiences on Windows 11. Based on the context, there are three main areas to address: calendar behavior, Outlook reliability after Windows updates, and the move away from older Mail/Calendar apps.

    1. Calendar time-slot and reminder issues
    • There is a documented issue where clicking in the Calendar selects the wrong time slot when multiple calendars are open, especially with dual monitors. This is specific to classic Outlook and does not occur in the new Outlook or Outlook on the web.
    • The fix for that issue has already been deployed from the service side; restarting classic Outlook picks up the change.
    • As part of Microsoft’s move to a single, modern Outlook experience, the new Outlook for Windows and Outlook on the web (Outlook.com or Microsoft 365 online) are the supported paths and are not affected by this specific calendar-click misalignment.
    • For calendar reliability (correct times, reminders firing), moving to the new Outlook for Windows or Outlook.com is the recommended long‑term solution.

    Practical steps:

    • If using classic Outlook and seeing wrong time slots when clicking or editing meetings:
      • Close and restart classic Outlook so it picks up the service-side fix.
      • If the issue persists and multiple calendars are open on dual monitors, temporarily use Outlook on the web or the new Outlook until the behavior stabilizes.
    • For more predictable reminders and time zones, consider configuring and using the new Outlook for Windows, which is the supported replacement and is actively updated.
    1. Outlook instability after Windows 11 updates
    • There are known cases where Windows updates have caused classic Outlook to hang, freeze, or behave unpredictably, especially with POP accounts and PST files (including PSTs on OneDrive). Symptoms include Outlook not responding, needing Task Manager to close it, and mail behavior issues.
    • These issues have been fixed by subsequent Windows updates. The guidance is to run Windows Update repeatedly until the system reports “You’re up to date,” which delivers the fixes.

    Practical steps:

    • Open Settings → Windows Update (or Update & Security on Windows 10) and install all available updates, restarting as required, until Windows reports “You’re up to date.”
    • This is particularly important if Outlook problems started immediately after a specific Windows 11 update; later cumulative updates often contain the fixes.
    1. Transition from old Mail/Calendar apps and data handling
    • Support for Mail and Calendar for Windows 10 ended on December 31, 2024. Those apps can no longer send or receive email or calendar events and can show “account settings out of date” because they are no longer supported.
    • Microsoft’s direction is to move to the new Outlook for Windows or Outlook.com for ongoing support, security updates, and feature improvements.
    • Any local emails, contacts, or calendar events stored in the old Mail/Calendar/People apps remain exportable and can be imported into the new Outlook for Windows.

    Practical steps for a more stable setup going forward:

    1. Standardize on one Outlook experience
      • Use the new Outlook for Windows (recommended) or Outlook.com in a browser for day‑to‑day work, calendar, and reminders.
      • Avoid relying on the retired Mail and Calendar apps, as they no longer function correctly.
    2. Ensure all Windows updates are applied
      • This brings in fixes for Outlook hangs and other post‑update issues.
    3. If using classic Outlook and seeing UI issues (drag/drop, calendar clicks)
      • Restart Outlook to pick up service-side calendar fixes.
      • If drag‑and‑drop or other UI actions break after a specific Windows 11 24H2 update, install the latest Windows 11 24H2 cumulative update, which contains fixes for classic Outlook UI problems.
    4. Data organization (folders, archive)
    • The context does not provide a step‑by‑step procedure for undoing automatic archiving or moving messages back from Archive, but it does emphasize that the supported path is to consolidate email and calendar usage into the new Outlook for Windows or Outlook.com, where ongoing fixes and improvements are delivered.

    If the calendar and reminder issues persist even after moving to the new Outlook for Windows and fully updating Windows, the next escalation path is to use the Outlook Tech Community or Outlook Forum on Answers to share exact symptoms (time zone, account type, screenshots) so engineers and support agents can review the specific configuration.

    References:

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