Extracting MSI files can be a pain.
Some compression programs (like 7zip) can unpack them, but leave the unpacked filenames as gibberish.
Many people recommend using msiexec (link to technet docs) on the commandline using the /a parameter (which does an administrative install effectively unpacking it), but others prefer integration in Windows Explorer.
msiexec /a PathToMSIFile /qb TARGETDIR=DirectoryToExtractTo
There are many tools allowing to unpack, and the best seems to be LessMSIerables by Scott Willeke which used to be on the (now defunct) pingpoet blogs, but got resurrected as lessmsi at oogle code.
Note that LessMSI doesn’t always work when msiexec /a works; for instance, I once got this error message:
Error: System.Runtime.InteropServices.COMException (0x00000003): Failed to close cab extract object, error: 3
Note that when you want to view MST files in addition to MSI files, then you need MSTVIEW from ORK XP or ORK 2003 (which you can get through the Office 2003 resource kit downloads page).
–jeroen
The Wiert Corner - irregular stream of stuff 