Here is the solution for cleaning up a crowded Installer folder:

http://blogs.msdn.com/heaths/archiv...ed-patches.aspx

In case the page goes away; essentially you download the Windows Installer Cleanup Tool from Microsoft which comes with a command line utility called msizap.exe. After installing the tool, run:

C:\Program Files\Windows Installer Clean Up\msizap G!

And it will automatically remove any .msp files that are not registered on your system. This process cleared over 6GB from a client's server system partition.

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http://support.microsoft.com/kb/274533