There is a problem with an Update (KB2823324) that Microsoft releases this April 09 2013, that could make the System unbootable.
From a recovery console run this command:
dism.exe /image:C:\ /cleanup-image /revertpendingactions
I did not test this procedure yet, so please use at your own risk
The article here:
http://support.micro....com/kb/2823324
Affected systems is 32bit:
How to recovery console:
http://www.bleepingc...command-prompt/
I hope this helps
Best Regards EdioIlha