Configuring the latex related commands
LaTeX comes with a number of command line tools to compile and manipulate LaTeX documents. The commands section defines there location and arguments. The default settings should work with the recent and standard LaTeX distributions, but you could have to modify them ("Configure TeXstudio" in "Commands"). To change a command, just click on the button at the end of the corresponding line and select the command in the file browser: TeXstudio will automatically adapt the syntax of the command.