Hi Nora,
You can disable the OneDrive photo slideshow feature by adjusting your settings in both the desktop app and the web version. On Windows 11 or the OneDrive desktop app, click the OneDrive icon in the taskbar, then click the gear icon in the top-right corner and select Settings. Navigate to the Notifications tab and toggle off the option that says "Notify me when 'On this day' memories are available."
If you're using OneDrive on the web, go to onedrive.live.com, click the gear icon in the top-right corner, and select Settings. Choose Options, then go to Notifications, and uncheck the box for "On this day memories are available." Be sure to click Save to apply the changes.
If you're currently stuck in the slideshow view and want to return to the traditional photo list, click the menu icon and select "View all photos" to go back to the standard chronological view. Let me know if you need help navigating these settings on your device. Hope this helps.
Best,
Jeric.