It is very simple and it won't take more than 30 seconds.
For example the software called abc located in D:/Softwares/vlc/abc.exe Add the folder path of abc.exe to system environment variables.
My Computer -> Click Properties -> Click Advanced system settings -> Click Environment Variables
Click on Ok.
now you can just open cmd prompt and you can launch the software from anywhere. to use abc.exe just type abc in the command line.