https://forums.autodesk.com/t5/inventor-forum/sp1-has-been-installed-but-not-according-to-iv/m-p/5893475#M355015 <P>Hi Mason-Paul,</P> <P>&nbsp;</P> <P>Sorry for your inconveniences. Your issue looks very similiar to a known issue. could you try below steps to see if your issue is solved?</P> <P>&nbsp;</P> <P><SPAN class="">1. Remove Inventor 2016 English Language Pack SP1</SPAN></P> <P>&nbsp;</P> <P>Msiexec.exe /uninstall {C2B4B6F5-2010-1033-0064-E0CB94366A9C} /package {7F4DD591-2064-0001-1033-7107D70F3DB4} /qb</P> <P>&nbsp;</P> <P><SPAN class="">2. Remove Inventor 2016 SP1</SPAN></P> <P>&nbsp;</P> <P><SPAN class="">Msiexec.exe /uninstall {C2B4B6F5-2000-1000-0064-E0CB94366A9C} /package {7F4DD591-2064-0001-0000-7107D70F3DB4} /qb</SPAN></P> <P>&nbsp;</P> <P><SPAN class="">3. Remove Inventor 2016 Update 1 (Inventor SP1 supesedes it and you can also install it again later)</SPAN></P> <P>&nbsp;</P> <P><SPAN class="">Msiexec.exe /promptrestart /qb /uninstall {D9AD67F6-F5D8-4377-8826-01687953EF10} /package {7F4DD591-2064-0001-0000-7107D70F3DB4} SETUP=1</SPAN></P> <P>&nbsp;</P> <P><SPAN class="">4. Install SP1 again.</SPAN></P> <P>&nbsp;</P> <P><SPAN class="">Regards,</SPAN></P> <P><SPAN class="">Baocheng</SPAN></P> Thu, 05 Nov 2015 04:26:28 GMT BaochengWu 2015-11-05T04:26:28Z