On windows, if you run a program such as Chrome.exe (Google Chrome Web Browser) via control + R (run) it will launch without a hitch as long as the browser is installed.
However, if you open the command line and you attempt to run “chrome.exe” it will complain that the executable is not found in the %PATH%
This is because Control+R also looks up the registry values within HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\
Which include all apps ever installed such as Chrome.exe, Firefox.exe, Excel.exe, Illustrator.exe, etc.
So if you are ever writing a program in your programming language of choice, using a Windows Registry check of the location (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths) for whatever.exe will be the perfect solution when that program is not in the System Environment variable %PATH%