How to change default virtual Hard Drive size from 32G

When I install Windows through parallels, it automatically creates a 32GB hard drive for Windows.

I'm not sure if 32GB of my actual hard drive are assigned to Windows or if the disk is small but can expand up to 32GB. How can I change this to 10GB so it takes up less space?

 

Parallels has created a disk file holding your Windows installation which is small but can expand up to 32GB, so the file is most likely not occupying 32GB on your hard disk at this time.

 

32 GB expandable virtual disks only initially take up 4 MB of disk space and expand as needed. Unless you actually put more than 10 GB of data on the virtual disk, it should not take up more than 10 GB of disk space. So there should be no need to decrease your virtual disk's capacity from 32 GB.