Do you want to see a list of products installed on your computer? What about a list of orphaned components? How about shared components? You can get this information for products that were installed using Microsoft Windows Installer technology (.msi) by running msiinv.exe tool.
If you can also use msizap.exe to remove any cached Windows Installer data files that have been orphaned, remove rollback information, delete MSI information about a product, and more. The tool is available as part of the Software development kit at http://www.microsoft.com/downloads/details.aspx?FamilyId=C2B1E300-F358-4523-B479-F53D234CDCCF&displaylang=en