PROBLEM
Merge snap­shot with with root vhd to one disk vhd

SOLUTIONS
- GO to C:\Program Files\Oracle\VirtualBox
— run VBoxManage.exe with those parameters

C:\Program Files\Oracle\VirtualBox>VBoxManage.exe clone­hd “D:\Snapshots\{667ad0f8-836e-418e-b68a-969f4b51f4cd}.vhd” e:\aaa.vhd
0%…10%…20%…30%…40%…50%…60%…70%…80%…90%…100%
Clone medi­um cre­at­ed in for­mat ‘VHD’. UUID: 4f8bf546-f2db-48b9-8af2-c62e0d751c3c

{667ad0f8-836e-418e-b68a-969f4b51f4cd}.vhd — is snap­shot, this snap­shot have path to orig­i­nal disk
aaa.vhd — will be disk, which it will have orig­i­nal and snap­shot disk 

- After that, you can Cre­ate new vir­tu­al machine, with aaa.vhd disk

SORUCE : superuser.com