By default, some programs will be installed while automatically being setup in order to be run from the command line.
For ex., [Win]+R ‘devenv’ launches Visual Studio.

I happened to run into this article which precises how to add some more:

Registry: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths

1. Create a new sub-key with the name of the executable file that you wish to add to the path (ex. eclipse.exe)
2. In this new key, add a string variable named “Path” containing the value of the the path to your new executable file (ex. “C:\Program files\eclipse\”)
3. The new key will already have an empty variable (Default). Edit it to have the string value of entire address of the new program executable (ex. “C:\Program files\eclipse\eclipse.exe”)