It looks like you’re asking about Total Commander version 10.52 and something related to wincmd.key (the license key file).

: One of TC’s strongest features is its portability. You can copy your installation folder, including WINCMD.KEY

  1. Open Total Commander.
  2. Click Help in the top menu bar.
  3. Select Register.
  4. Navigate to the location of your wincmd.key file and open it.
  5. Restart Total Commander. The nag screen should disappear.

Why the "WincmdKey" keyword?

The internal name for Total Commander is wincmd. Therefore:

What about commercial use?

For a company, each employee who uses Total Commander should have their own license, or the company can purchase a volume license. Using a single wincmd.key across an entire organization is illegal.