March 2009: The XP AutoRun blocker that didn’t
It took Microsoft forever to post a patch that disabled AutoRun in Windows XP. AutoRun, indicted as the culprit behind mass Conficker infections, deserved to die, but Microsoft's first and second attempts to talk people through the disabling procedure didn't work.
The final solution is so incredibly convoluted that pages of KB 967715 are devoted to explaining the interactions of all the patches, both delivered via automatic update and manually downloaded. It's complicated. Bottom line: If you only installed one automatic update, you might've thought that you fixed AutoRun, but you didn't. It took several patches over several months to finally get it right.