When starting Vault Explorer (all flavours) 2013/2014/2015. the loading splash screen stays on top of everything while Vault loads. There is no way to hide it. This means you can't look at or do anything else in windows while you wait for the application to load. Where it is particularly frustrating, is when an error message pops up on loading and ends up hidden behind the splash screen. The only way you can continue, is to click on the message box in the task bar, and then use "Alt+Spacebar+M" and the arrow keys or mouse, to move the error dialog out from behind the splash screen.
I believe this is a regression. I'm sure that this behaviour was not present in earlier releases, but I could be wrong. More importantly, it is inconsistent with every other Autodesk product I have used. Usually, while the application is loading, you can click somewhere other than the splash screen, and it will hide it behind the active window.