After holding down Shift+Ctrl, a box comes up asking if I want to "Allow Movie Studio to make changes to my computer?" But after clicking yes, the program opens as normal without any further dialogue boxes.
My understanding is it doesn't work from Windows Tiles or Start Menu. It needs to be done from a desktop icon that links directly to the programme .exe file. Find the programme exe and create a shortcut on your desktop. Then use that with Shift+Ctrl and you should find it works.