This article describes some methods to troubleshoot some specific issues in Windows 2008 R2 migration to Amazon EC2 cloud.
Check the image VHD file
In case you encounter an error after "Preparing the image uploaded for cloud use" stage, check if created image is valid.
Attach your C.VHD image created in the transfer process via Windows Disk Management Console (see http://www.thomasmaurer.ch/2010/12/howto-attach-detach-vhd-in-windows-se...) with read-only flag off.
After the disk is attached check the following:
The disk should contain one volume.
Assign drive letter to it, try to explore the volume
Check Windows directory is present on it
In case one of this checks fail, your image is corrupt. Detach C.VHD deleting it. Restart the migration process.