Policy
Number of workbooks in the Recent Workbooks list
This policy setting specifies the number of entries displayed in the Recent Workbooks list that appears when users click Open on the File tab in Backstage view. If you enable this policy setting, you can specify the number of entries to be between 0 and 50. If you set the number to 0, all pinned and unpinned entries are hidden. If you disable or do not configure this policy setting, a maximum of 25 items will be displayed in the Recent Workbooks list. Note: If you want to prevent items from being added to the Recent Workbooks list entirely, you can enable the "Do not keep history of recently opened documents" Windows policy setting.
7b749fa62ce3 L_Recentlyusedfilelist Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\excel\file mru\max displayPolicy notes
This policy setting specifies the number of entries displayed in the Recent Workbooks list that appears when users click Open on the File tab in Backstage view. If you enable this policy setting, you can specify the number of entries to be between 0 and 50. If you set the number to 0, all pinned and unpinned entries are hidden. If you disable or do not configure this policy setting, a maximum of 25 items will be displayed in the Recent Workbooks list. Note: If you want to prevent items from being added to the Recent Workbooks list entirely, you can enable the "Do not keep history of recently opened documents" Windows policy setting.