In Microsoft System Center Virtual Machine Manager 2008 R2, you remove a VHD from a VM. You expect that .vhd file is detached from the VM. However, .vhd file is actually deleted on Hyper-V server. To resolve, download hotfix and apply, you’ll receive following warning: You have chosen to remove virtual hard disks from virtual machine VMName. This action'll delete .vhd files. Do you want to continue? If you click Yes, .vhd file’s deleted from Hyper-V server. If you click No, .vhd file remains attached to vm and isn’t deleted from Hyper-V server. If you want to remove a VHD from a vm without deleting VHD file on Hyper-V server, use Hyper-V Manager console, KB976246.