Don't panic: Microsoft mistakenly posted a 'test' Windows update patch

Microsoft confirmed Wednesday that a suspicious-looking update pushed out to Windows machines globally in the early hours was nothing more than a test gone errant.

It's not immediately clear what was inside the patch, or whether it modified any Windows files. In any case, the Windows Update system is a core and vital part of keeping computers around the world up-to-date. Shaking confidence in that system is going to have a lasting effect, especially in a day and age of almost daily hacks and ongoing government surveillance.