Windows Virtual PC Cannot attach the virtual hard disk

Hello,
I have created Virtual Hard Disk with Microsoft Disk2VHD toll.
On it I have done some backup files, but only on it I have back up files.
When I want to use this Virtual back up error message appears.
Please help, I need to solve this problem it its possible.
Thank you in advance.
Camella

Windows Virtual PC
Cannot attach the virtual hard disk to the virtual machine. Check the values provided and try again.
OK
