There would be several reasons causing Nero Video fails to show its application window. If Nero Video could not start, MediaHome could not start but Recode could start, you could do below steps:
1.Open "Color Management" in Control Panel
2.Click "Advanced" tab
3.Check the "device profile" set, set is "System default (sRGB IEC61966-2.1)
4.Reopen Nero Video again