According to the Canonical, Optimised Ubuntu desktop image is available in Microsoft Hyper-V gallery. Hyper-V is Microsoft’s hardware virtualization product and it runs each virtual machine in its own isolated space.
The optimised Ubuntu Desktop 18.04.1 LTS Hyper-V image is available in the Hyper-V Gallery on Windows 10 Pro. Enhanced Session Mode has been added in latest image which provides integration between a Windows host and the Ubuntu virtual machine running in Hyper-V. Meanwhile, On top of running Ubuntu in a virtual machine, you can use Windows Subsystem for Linux.
Read more about this development here.