In Windows 11/10, Windows Backup notifies end-users to configure Windows Backup. Notifications like Backup in progress can appear in the Action Center after seven days without configuring Windows Backup or when an end-user attaches an external hard drive.
Disable Windows Backup in progress notification
You can disable the Backup in progress Windows Backup notifications via Control Panel, REGEDIT or GPEDIT. You can do this if you do not intend to enable Windows Backup, but instead use a third-party backup solution,
1] Using Control Panel
You can do the following.
Open Control Panel\All Control Panel Items\Action Center\Change Action Center.
Check or uncheck the options you want, click OK and Exit.
2] Using Windows Registry
Windows Backup notifications are controlled by a registry key. This registry key is not present in default Windows installations. To disable Windows Backup notifications, you must manually add a registry key.
To do so, open regedit and navigate to the following location:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsBackup
Now under WindowsBackup, in the RHS pane, open a new DWORD and name it as DisableMonitoring, and set its value to ‘1‘.
Exit regedit.
If this key is set to 0, or if this key does not exist, then Windows Backup will display notifications to the end-user to configure Windows Backup.
If this key is set to 1, and an end-user has not already configured Windows Backup, then notifications to configure Windows Backup will not be displayed to the end-user when a user attaches an external hard disk.
3] Using Group Policy Editor
Open GPEDIT.msc and navigate to the following settings:
User Configuration > Administrative Templates > Start Menu and Taskbar.
Double-click the Remove Notifications and Action Center in the settings box and select Enabled.
Click Apply and restart the computer.
I hope this helps.