Community
This matter came up with 2014 last year and was able to be changed - see below.
http://forums.autodesk.com/t5/Installation-Licensing/How-to-edit-Inventor-2014-setup-ini-for-Vista-64-installation/m-p/3882287#M61557
However this action does not seem to work for 2015. Is there a work around?
Regards,
John
Have you also tried to run setup.exe in XP compatibility mode?