1. Shutdown VM
2. Expand VHD file in VM’s properties (in Hyper-V)
3. Switch on VM and check drive expansion is reflecting in VM’s Disc Management
4. Switch of VM
5. Mount VM’s VHD file in Hyper-V host - Disk Management>Action>Attach VHD
6. Expand VHD using Hyper-V host’s Disc Management MMC
7. Make VHD offline and then unmounts VHD
8. Start VM, now drive must showing added space.