Once the install is complete login with:
Username is root
Password is eve
Complete the setup wizard
Once the wizard is complete, shutdown the computer
Use a usb key and boot into gparted live environment: https://sourceforge.net/projects/gparte ... o/download
Do not just download the latest version of gparted live, you must use version gparted-live-1.3.1-8-amd64.iso (some dependencies are missing for lvm2 on the latest version)
Once you're in the live environment, open the terminal and run
sudo lvreduce --resizefs --size 300G /dev/ubuntu-vg/ubuntu-lv
This command will reduce the partition to 300 gigabytes and the remainder will be unallocated. Obviously you don't have to use 300G, change it to whatever you want.
Open GParted, look for the partition that has a file system of lvm2 pv. Right click it and choose Resize/Move. At the top of the window you'll see a long rectangle that represents the partition. On the right side of the rectangle hover your mouse until it turns into
, then click and drag the partition border to the left until it stops. This will leave your 300G lvm2 partition intact and the remaining will be unallocated. Click Resize, then click the checkmark in the toolbar to submit the operation. Click applyYou're now ready to install Windows
When it asks, "Which type of installation do you want?", choose Custom: Install Windows only (advanced)
Highlight the line that contains "Unallocated Space" and click next to install Windows
That's it! Someone smarter than me could probably figure out how to have a grub boot menu pop up so you can choose what to boot into. For now, I just boot into bios and manually select my boot volume.