Problem with Natbib after installing biblatex [closed]

I installed BibLaTeX, and I couldn't get it to work so I decided to go back to my old BibTeX natbib - but now I can't get my references back. What's going on...? Do I have to redo the installation of BibLaTeX?

Code:

\documentclass[11pt,a4paper]{article}

\usepackage[sort]{natbib}

\begin{document}

\bibliographystyle{plainnat}
\bibliography{References}\thispagestyle{empty}

\end{document}
-
Welcome to TeX.sx! A tip: If you indent lines by 4 spaces or enclose words in backticks `, they'll be marked as code, as can be seen in my edit. You can also highlight the code and click the "code" button (with "{}" on it). –  Guido Nov 20 '12 at 18:41
Have you removed the auxiliary files (.aux, .bbl, ...) ? It is a typical problem when one switch from one bibliography style to a different one. By the way, using \thispagestyle{empty} after \bibliography might not produce the right results (if the bibliography spans over two or more pages) since it is executed at the end of the bibliography. –  Guido Nov 20 '12 at 18:43
Are you actually seeking \pagestyle{empty} BEFORE the bibliography command? Have you tried compiling several times? –  Nicholas Hamilton Dec 15 '12 at 16:40