Method 3. Extend C drive space via DiskPart CMD Why should you increase C drive space? Is your computer running slower than usual, or are you constantly seeing “Low Disk Space” warnings?

Rather than destroying the existing VM to expand the disk to allow for the installation, users can–with some manual effort–expand the existing disk image used with Windows 10 in a VM.

If you need to increase Disk size in VirtualBox, you can use GUI or CLI. Follow the instructions mentioned in this post to the size of the partition.