<p>There is a relatively new tool called <a href="http://www.homedev.com.au/Free/PatchCleaner">PatchCleaner</a> which detects and can delete old MSI/MSP files.</p>
<p>From the PatchCleaner page:</p>
<blockquote></blockquote>
<p><strong>Windows Installer Directory</strong> When applications are installed and updated on the Windows Operating System a hidden directory<br>
“c:\Windows\Installer” is used to store the installer (.msi) files and<br>
the patch (.msp) files.</p>
<p>Generally these files are important as during updating, patching or<br>
uninstalling software it will use the .msi/.msp files. If you<br>
blanketly delete all the files in this folder, you will find yourself<br>
needing to rebuild windows.</p>
<p>Over time as your computer is patched and patched again, these<br>
installer files become outdated and orphaned. They are no longer<br>
required, but they can take up many gigabytes of data.</p>
<p><strong>PatchCleaner</strong> PatchCleaner identifies these redundant/orphaned files and allows you to either:</p>
<p><em><strong>(Recommended) Move them to another location. Si vous voulez to play it<br>
safe, just move them to another location, and vous pouvez always copy them<br>
back. Delete them.</strong></em></p>
<p>First use the move option and wait a few days before you delete the moved files.</p>
