Texmaker (Windows version) - first use - Error: Log file not found!

You also need to install a TeX distribution, i.e. MiKTeX or TeX Live. The TeX distribution contains all the machinery needed to process source code and produce typeset documents; Texmaker is just a front end.

It is not enough to just have the TeX distribution installed, it is also necessary to add the MiKTeX bin to the path or else change the commands in the configuration to use the full path to each executable (i.e., if you look at the actual commands being called they are just "latex", "pdflatex", etc. without the path to the executable).

In my case I had MiKTeX installed and working with another editor, but it would not work with TeXMaker - adding the path to the bin to my window Path environment variable resolved the issue for me. For me this path is:

C:\Program Files\MiKTeX 2.9\miktex\bin\x64

If you still get error: Log file not found!, when using Texmaker when you have done everything (installed MiKTex, installed Texmaker, and checked if the binary for MiKTeX is already in your windows environment varible) then simply close the Texmaker and reopen it as an administrator. Right click on the executable for Texmaker and "Run as administrator". This worked for me!