For a hassle-free experience, place your wincmd.key directly in the (e.g., C:\totalcmd\ ). Why? Because when you run the installer for 10.52, it automatically detects the key. If you use a portable version or run with admin rights, storing it in the app folder avoids Windows UAC conflicts.
The WINCMD.KEY is your registration file. While Total Commander is famous for its generous "nag screen" trial (which never expires but asks you to click a button), having a valid WINCMD.KEY makes the experience better for several reasons: Location of WINCMD.KEY - Total Commander - ghisler.ch total commander 1052 wincmdkey better