You do not have to install Service Pack 1 in order to install Service Pack 2.
Service Pack 2 includes the most recent fixes, as well as all fixes included in Service Pack 1.
This Service Pack 2 updates Autodesk Inventor 2014 or Autodesk Inventor Professional 2014 for all operating systems and languages.
For installation on Windows 8.1 OS please read Technical Solution TS22238097.
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