Microsoft warns that when using SCVMM 2008, a Physical to Virtual (P2V) conversion of a Windows Server 2003 system fails due to Volume Shadow Copy Service on the P2V source machine. You'll receive an error similar to following (pic).
"This can occur because a corrupted subscription is detected by the COM+ system causing it to stop processing further VSS providers. COM+ is essential to the Volume Shadow Copy Service."
A Hotfix is available and is already included in SP3 for Windows Server 2003 and requires that Windows 2003 SP1 or SP2 is already installed. The hotfix is also available separately:
KB968447: The COM+ Event System stops processing the query for matching subscriptions when it detects a corrupted subscription on a Windows Server 2003-based computer.