 setting the PG flag to 1 when the PE flag is set to 0, or setting the CD flag to 0 when the NW flag is set to 1).</p>
<p>If an attempt is made to write a 1 to any reserved bit in CR4.</p>
<p>If an attempt is made to write 1 to CR4.PCIDE.</p>
<p>If any of the reserved bits are set in the page-directory pointers table (PDPT) and the loading of a control register causes the PDPT to be loaded into the processor.</p></td></tr>
<tr>
<td>#UD</td>
<td>
<p>If the LOCK prefix is used.</p>
<p>If an attempt is made to