The default value is set to show 10 documents, but you can increase that with a registry tweak. As always please backup your registry first before you performing this tweak. Follow the steps given below:
  • Click on start menu search box
  • Open up regedit.exe
  • Then navigate to the following key:
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
  • Add a new DWORD 32-bit value named MaxRecentDocs into the right-hand pane
  • Then double-click to open
  • Change Base to Decimal
  • Enter any value you want for the list into the Value data field
  • Press OK and close Registry Editor
Now you can see the increase in the number of recent items in Start Menu.