After adding the old web server’s VHD to get the web files onto the new web server, I tried to remove the old VHD…only to fail with the following error:
Error Removing Hard Drive
Failed to remove device ‘Microsoft Synthetic Disk Drive’: Generic failure (0x80041001)
Providing no hint at why this happened aside from “cannot be deleted because a logical disk object is still attached to it.” I powered on the VM and offlined the disk. Then powered off, and tried to remove the VHD again. SAME ERROR! Ok…Power on VM again, uninstall the HDD from device manager. Power off. Same result. The only thing I could think of was that I was doing this from my terminal server – which is a 2008 box- not 2008 R2. So, I tried from a 2008 R2 with 2008 R2 Hyper-V tools, and Bam! That did it.
In conclusion, if there is a VHD that was created using Hyper-V 1.0 (2008) mounted to a VM created with Hyper-V 2.0 (2008 R2) then you must use the 2008 R2 (or Win7) Hyper-V manager to remove the disk – it adds just fine.