This morning I discovered that my Windows Defender no longer worked. I was prompted with a non-intuitive error message:

Application failed to initialize: 0x800106ba. A problem caused Windows Defender Service to stop. To start the service, restart your computer or search Help and Support on how to start a service manually.

Following one of the recommendations -- reboot -- did not yield any positive result. I decided to do a System Restore to a point before the last Windows Defender definition was updated thinking that the definition may have corrupted Windows Defender. To my dismay, System Restore no longer works either.

It did not immediately dawn on me that the Beta 2 version I was running had expired and I simply had to upgrade to the release version that Microsoft has provided free of charge at the following link:

http://www.microsoft.com/downloads/details.aspx?FamilyId=435BFCE7-DA2B-4A6A-AFA4-F7F14E605A0D&displaylang=en

You would think Microsoft would provide the proper expiration warning for a product that expires after a certain date. No such luck.

So, there you have it. If you ran into the same issue, head on over to Microsoft and download the Release version of Windows Defender.