Known Issue - FirstBootFailure. Windows system drive is not C:

Symptoms: 

FirstBootFailure: This import request failed because the Windows instance failed to boot and establish network connectivity.

When Windows system drive is not C:

Explanation: 

Our Windows installation should be located on drive C:. 

Amazon EC2 fails to accept images of Windows installed on drive other than C:.

Solution: 

Change system drive letter to C via Windows Disk Management or via registry.

Notes: 

See Microsoft KB on how to change the system drive letter via registry  http://support.microsoft.com/kb/223188