Use rfues to create a win boot disk (can be downloaded in i tell you) and debian12 (Tsinghua Source download is faster) boot disk
Install Windows first: The motherboard sets the USB drive to boot first, and then restart it after inserting the USB drive. Follow the prompts to go down step by step (remember to leave enough space to install debian12)
After the Windows installation is completed, insert the debian 12 boot disk and restart
Follow the system prompts to install normally. Debian will automatically recognize the startup partition of Windows and write EFI boot to the corresponding partition.
After completing the debian installation, set priority boot option in the motherboard. Debian12 will provide window options. Select according to the requirements to enter the corresponding system.
In debian12, you can set the default entry system. Use the root user to select the default startup item in /etc/grub/ as window. The first item defaults to linux (set default ='0'), and change it to the corresponding windows startup item (set default ='2')
After restarting, it will enter the Windows system by default.