Symptom: When producing pdfs with latex (miktex distro) it uses bitmap fonts, resulting in text that it is not possible to either select or search.
Solution: install the cm-super fonts with the miktex package manager (large package), or use the \usepackage{lmodern} command to use the lmodern fonts that are included with miktex.

This post at miktex support forum outlines the symptoms, cause and solution.