If you've ever tried to grab an old Virtual Server .vhd and fire it up in Hyper-V you'll likely have run into a troublesome issue if the Virtual Machine Additions were not installed previously they seem impossible to get rid of while running under Hyper-V. And since Hyper-V Integration Services won't install over Virtual Machine Additions you have to put up with all sorts of little issues with your image.
I found this set of instructions which worked remarkably well and has saved me countless hours of inconvenience porting over old vhd images. I have to give credit to Martec on technet for this great solution.