The Windows 7 and Ubantu dual systems are installed on the computer because Linux systems use less and the default startup items are very intolerable, so you have to change Windows as the default startup item.
Because the system boot program on the computer is grub, the change will of course fall on the Linux system.
change/boot/grub/grub.cfg The default load startup item in the file (default itself to load the first boot entry, default= "0"), because the file is more important before you make a backup of it (CP/ Boot/grub/grub.cfg/boot/grub/grub.cfg.back)
There are 5 boot options on the computer, and Windows is the 5th option, so the default startup item is changed from the original default of 0 to 4.
Before the change (Grub.cfg.back is backed up before the change):
After the change:
Note that the Grub.cfg file is a read-only file so the changes need to be forced by the root user.
Windows and Linux Dual Systems-Change the default boot order