LaTeX on Windows
Texpile can install TeX Live for you. See From Texpile. To install a distribution yourself, read on.
Run install-tl-windows.exe (recommended) from CTAN for TeX Live, or install MiKTeX. Restart Texpile if it is open.
You only need one of the distros above. In the rare case where you have multiple TeX distributions installed, you can pick one with the LaTeX picker in Preferences › Programs & Compiler.