I've been working on this for the last three hours and found no clue. This morning I found the blog Certificates with LaTeX and downloaded the tex file certificate.tex. When I compile this in my emacs I run into the following error report:
ERROR: LaTeX Error: File `nowidow.sty' not found
I followed the instruction on this post:
Where do I place my own .sty files, to make them available to all my .tex files?
and put the nowidow.sty into the directory: /usr/local/share/texmf/nowidow
But the error report still pops up. Did I put the file in the wrong directory or am I missing other important steps? Could anyone help me? My system is Ubuntu 12.04.