I wanted to use gnuplottex to create my plots directly in TeXstudio but so far I didn't get any results. When I use the following I get
Conversion of document-gnuplottex-fig1.gnuplot failed.
Please convert document-gnuplottex-fig1.gnuplot manually.
and
Der Befehl "gnuplot" ist entweder falsch geschrieben oder konnte nicht gefunden werden.
which translates to "The command "gnuplot" is mistyped or couldn't be found".
Also, -shell-escape is enabled.
Here's my MWE:
\documentclass{scrartcl}
\usepackage{graphicx}
\usepackage{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage[miktex]{gnuplottex}
\usepackage{pgfplots}
\pgfplotsset{compat=1.14}
\usepackage{microtype}
\begin{document}
\begin{gnuplot}
set xrange [-10:10]
yet yrange [-10:10]
f(x) = x**2 + 5*x
plot f(x)
\end{gnuplot}
\end{document}

shell-escape, see e.g. https://tex.stackexchange.com/questions/99475/how-to-invoke-latex-with-the-shell-escape-flag-in-texmakerx (edit: sorry, didn't see you had enabled it). With that, fixing the typo inset yrange, and removing[miktex](because I don't use MikTeX), it works fine. – Torbjørn T. Nov 26 '17 at 00:16