If you apply the following registry entries to your computer, the file assocations with Inventor view 2012 will work for anyone who logs in. The key is that file assocations for the computer are stored in HKLM\Software\Classes. This also works for Terminal Servers as well. This associates IPT and IDW file types to the viewer.
Hi, not sure if this is relevant but i have found that Inventor file associations were not copied to domain accounts on some computers we have here. To fix I exported HKCU\Software\Classes from a local user account and imported it into the affected domain account.