LyX ⇒ Converting to pdf in a portable LyX installation

[SebLavK]

I've succesfully installed a portable installation of LyX and MiKTeX followint these instructions: https://wiki.lyx.org/Windows/PortableInstallation

Everything works well, except when trying to export to pdf using pdflatex. How can I set, or install, pdflatex and direct LyX to use it within the USB?

I installed it using a computer with LyX already installed on it, so maybe the portable installation got directed to the pdflatex of the computer.