Need help with installation sorting

just check before with gparted or

sudo parted -l 
sudo fdisk -l

for your main desktop:
check all disks are GPT

→ check that /boot/efi windows is on SSD not Nmve
be careful on update windows

→ on nmve create /boot/efi for Eos , ( 512Mo )

for dual boot ,
see this How difficult is it to set up EOS with a dualboot alongside windows? - #7 by kjw