Fixing Undefined Control Sequence \printglossary error when running LaTeX.
This can happen with older tex files after upgrading to a later version of MikTeX.
From the nomencl documentation:
In the latest version of nomencl the commands \makeglossary and \printglossary were replaced with \makenomenclature and \printnomenclature.
Simply replace the above commands to eliminate the error. You could also enable compatibility mode as described in the documentation.
See the Documentation for the nomencl package PDF on CTAN for more information.