I needed to develop an utility application in Qt, which should work in Windows. I use Linux, and this is no problem since Qt is crossplatform, but anyway, to make sure resulting application works in Windows as intended, I've installed Qt in Windows guest OS in VirtualBox.
Surprisingly, at the time of writing this, there were two issues running Qt Creator in Windows guest OS.
First of all, Qt Creator crashed immediately when I start it, complaining about VBoxOGLpackspu.dll. After some googling, I found out that there is a bug in VirtualBox, and that we can work around this by disabling 3D acceleration in virtual machine.
Having that done, Qt Creator runs, but doesn't show anything useful. This is because the VirtualBox has problems rendering the QML apps/widgets, and the welcome screen in QtCreator is a QML widget. ( source: http://stackoverflow.com/questions/21127335/why-does-qt-creator-3-0-0-welcome-mode-not-work-in-vm )
So, to fix this, perform the following:
After this, Qt Creator works under Windows guest OS normally.