What are default program files in the 'C:\Program Files\' directory on Windows 10 Pro?

On a new Windows 10 Pro system, you should have the following default programs in the 'C:\Program Files\' directory:

C:\Users\fyicenter>dir 'C:\Program Files\'

Common Files - Common files shared by multiple programs
Internet Explorer - The IE 11 Web browser
Windows Defender - An antivirus program
Windows Mail - A contact directory manager
Windows Media Player - A multi-media player
Windows Multimedia Platform - An empty placeholder
Windows NT - Accessory tools: WordPad
Windows Photo Viewer - A photo or graphics file viewer
Windows Portable Devices - An empty placeholder
WindowsPowerShell - The PowerShell

32-bit versions of default programs are also stored in 'C:\Program Files (x86)\'

C:\Users\fyicenter> dir 'C:\Program Files (x86)\'

Common Files
Internet Explorer
Microsoft.NET
Windows Defender
Windows Mail
Windows Media Player
Windows Multimedia Platform
Windows NT
Windows Photo Viewer
Windows Portable Devices
WindowsPowerShell

If you see any other programs listed in those 2 directories, it most likely installed by some applications.

⇒ Default Services on Windows 10 Pro

⇐ Empty "Uninstall a Program" List on Windows 10 Pro

⇑ Windows 10 Pro Edition

⇑⇑ Windows 10 Tutorials