Activation prompt after moving VHD from Virtual Server to HyperV

After moving an activated copy of Windows Server 2003 or Windows XP operating system vhd from Microsoft Virtual Server to Hyper-V  

We may get an Activation Prompt

 ------------------------------------------------------------------------------------------- 

Windows Product Activation

------------------------------------------------------------------------------------------ 

Since Windows was first activated on the screen on this computer, the hardware  

on the computer has change significantly. Due to these changes, 

Windows must be reactivated within 3 day 

Do you want to reactivate Windows now? 

          | Yes |    | No | 

--------------------------------------------------------------------------------------------

When a vhd is moved from Virtual Server to Hyper-V,  hardware changes are triggered due the difference in architecture between Virtual PC and Hyper-V. These changes may result in re-activation being required.  

These hardware changes are due to differences in how Virtual Server and Hyper-v present the virtual devices to the guest operating system. One distinct difference is Hyper-v uses synthetic devices that  pass data along the VMBus to the physical hardware resources. While, Virtual Server uses software emulation  that emulates a physical hardware using software. 

Further, Hyper-V provides the ability to support up to four processors in a virtual machine environment, which is not available in Virtual Server or Virtual PC

To resolve this issue re-activate the installation of Windows when prompted.  

For more information about Microsoft Product activation, please reference the following link:

       http://www.microsoft.com/piracy/mpa.aspx 

For more information on moving Virtual Server guests to Hyper-V refer to the following guidelines. 

http://technet.microsoft.com/en-us/library/dd296684.aspx 

http://blogs.technet.com/askcore/archive/2008/09/19/migrating-to-hyper-v-from-virtual-server-or-virtual-pc-tips-and-suggestions.aspx