The PortableApps project takes windows applications and prepares them to get installed on a pen drive. They should take care of all the registry and permission issues. If this is your purpose, you should ask there for help as this isn't our business.
We build LibreCAD to run on desktop machines and supply installer for this purpose, you find them on our sf.net account.
https://sourceforge.net/projects/librecad/files/Windows/It is recommend to use these installers unless you really need a portable installation.
The --debug switch doesn't work on Windows as a GUI application doesn't have access to the terminal it was started from. This works only on unix like systems.
Armin
investing less than half an hour into Search function can save hours or days of waiting for a solution