In some situations when the system is not responding the screen, or the window for a application will get a Haze over it. Does it look something like that?
If you open the Event Viewer (eventvwr.msc) and look for error or warning messages, do you see any that might be associated with the event?
Is your system taking a minute to display the Desktop icons after it has booted into Windows, or are you referring to total boot time?