I just tested portable KiCad pre-5 in Windows 10, meaning that I can copy KiCad into e.g. a usb stick and run it from there, hopefully without leaving any traces into the system. I just didn’t test it with an external drive yet, nor did I do any in-depth testing.
I just copied a whole existing KiCad installation from C:\Program Files to another folder. Then I made this batch script:
set KIPATH=%~dp0 set KICAD_CONFIG_HOME=%KIPATH%\userfiles\conf rem Set all possible paths if you want, but KiCad guesses at least most of them correctly %KIPATH%\bin\kicad.exe
and named it “kicad.bat”, and saved it in the new KiCad folder. I created userfiles\conf\ manually under the new KiCad folder.
KiCad can be run successfully by double clicking kicad.bat. Pcbnew and eeschema find the correct libraries.