There is a bug in the K1000 5.3 agent that causes the "Unexpected Shutdown" dialog box to pop up after a restart when the agent service is running. It's currently scheduled to be resolved in version 5.4 of the agent.
As a work-around:
1. You can stop the AMP agent service before rebooting manually. This would be done through services or through the command line:
net stop ampagent
2. You can create a batch file and put it on the desktop that stops the ampagent and forces a restart.
This works, but you have to run as administrator (e.g. right-click on it and select run as) otherwise you don't have rights to services. You could also include administrator credentials in the batch if you wish.
Batch file contents:
start /wait net stop ampagent