Win10 dual system settings default method to start the operating system and wait time

Win10 preview version is still unstable, many users install WinXP/Win7/Win8.1/Win10 dual system or multiple systems (see the system home "How to install Win10 dual system?"), so that when the computer starts Let users select the operating system they need to run in dual or multiple systems.

But there will be a default operating system. When the countdown is over, if you do not select an operating system, the default operating system will be started. So how do you customize the default startup operating system and wait time? The method is as follows:
Method 1: Set in the system startup menu
When the computer is booted to the “Select operating system” interface, click the following “Change default value or select other options” to enter ““ ;Options  interface. Figure:

Click “Change Timer” to enter the interface to modify the waiting time. Figure:

Select the appropriate waiting time, usually 5 seconds. If you think that 5 seconds is still too long and you want to change to a shorter time, you need to use the following method two to set it in "System Configuration".