It's Not A Bug. It's A Security Feature.
Sure, the latest critical patch from Microsoft might lock you out of your PC or empty out your network connections folder. But not to fear, says Microsoft. After all:
Even if users experience PC trouble after installing the patch, they will still be protected against any attack exploiting the Windows flaw, a Microsoft representative said.
Which, you know, if you can't get onto your PC or access the network, would be pretty much true. Although maybe not in precisely the most user-friendly fashion.