Elastic Compute Service:What do I do if the Windows operating system of an instance cannot be activated due to corrupted instance components?

Problem description

After the Windows operating system of an instance starts, the desktop background becomes black and a message similar to "This copy of Windows is not genuine" is displayed in the lower-right corner. When you manually activate the operating system by performing the steps described in the "How do I use KMS domain names to activate Windows instances in VPCs?" topic, the following error is returned:

On a computer that runs a Microsoft Windows non-core edition, run slui.exe 0x2a 0x80070003 to display the error text. 
Error: 0x80070003

Cause

The preceding issue occurs because components of the instance are corrupted.

Solution

1. Connect to the ECS instance.

   For more information, see Connect to a Windows instance by using a password or key.

2. Start Command Prompt and then run the following command to fix the components:

   sfc /scannow

3. If the components cannot be fixed and snapshots are created, use snapshots to roll back the disks of the instance. This way, the Windows operating system can revert to a state in which the operating system is activated. For information about how to use a snapshot to roll back a disk, see Roll back a disk by using a snapshot.