Simply having the file on your desktop isn't enough. You must place it inside the Windows Installation Media structure.
You might be wondering: “Can’t I just create my own Ei.cfg file in Notepad?”
With the Ei.cfg file present and set to PROFESSIONAL , Setup bypasses this selection screen entirely and defaults to Pro, asking only for a key at the end of the installation. Download Ei.cfg File For Windows 8.1 Pro
The Ei.cfg file (Edition Identifier Configuration) is a small, simple text file located inside the \sources folder of a Windows installation disk (ISO file). Its primary function is to tell the Windows Setup program exactly which edition of Windows to install when no product key is provided.
Now, when you boot from this USB drive:
: Set to Professional to specifically install the Pro version. You can leave this blank if you want the installer to show a list of all available editions (Home, Pro, etc.).
ei.cfg is a small configuration file that controls in Windows 8.1, 10, and 11 setup media. When you download an official Windows 8.1 Pro ISO from Microsoft, this file is not normally included —but adding or modifying it unlocks specific setup behavior. Simply having the file on your desktop isn't enough
The Ei.cfg file is just one of three ways to control Windows Setup behavior. Here is how they compare: