Best is to contact e-on's tech support. You shouldn't have to install Pro Studio before Infinite, even if sidegrade, you would just need to give every serial number you had, if your ProStudio was an upgrade from 5 Esprit, you should enter each serial Vue asks ( 5 Esprit serial, and then every add -on module serial one by one), if you bought 5 Pro Studio without upgrading from 5 Esprit, you should only need your Pro Studio serial.

Before going through the process of entering serials, you need to download the latest official update for your Infinite ( 5.09), and run it right after reinstallling 5 Infinite, and then only, open Vue and enter your serials.