You could go to your "SHOWTHREAD" template, and locate the code:
PHP Code:
<li><a href="{vb:raw $vboptions.vbforum_url}{vb:if "$vboptions['vbforum_url']", '/', ''}printthread.php?{vb:raw session.sessionurl}t={vb:raw threadid}<vb:if condition="$perpage">&pp={vb:raw perpage}</vb:if><vb:if condition="$pagenumber">&page={vb:raw pagenumber}</vb:if>" accesskey="3" rel="nofollow">{vb:rawphrase show_printable_version}</a></li>
and change it to:
PHP Code:
<vb:comment><li><a href="{vb:raw $vboptions.vbforum_url}{vb:if "$vboptions['vbforum_url']", '/', ''}printthread.php?{vb:raw session.sessionurl}t={vb:raw threadid}<vb:if condition="$perpage">&pp={vb:raw perpage}</vb:if><vb:if condition="$pagenumber">&page={vb:raw pagenumber}</vb:if>" accesskey="3" rel="nofollow">{vb:rawphrase show_printable_version}</a></li></vb:comment>