[InclinedPlane]

My favorite power management bug is in the Windows 7 original release. The default configuration was to put the computer to sleep after 30 minutes of inactivity. In many situations this was fine however what is the first thing that you do with a new OS installation? Install patches of course. And the way that Windows works is it does this in two phases, it'll do some installation work while a user is a logged in, and it'll do additional installation and configuration stuff after a reboot but before a user can login. Which the OS isn't smart enough to understand doesn't count as "idle time". So at some point after Windows 7 came out the size and installation time of all the patches (especially on a spinning hard drive) would cause the OS to get into a reboot loop. It would boot, immediately try to apply the configuration updates for installed patches, timeout and be triggered to go to sleep, rollback the changes, and then it would start again. Eventually some failure threshold would get triggered and you could actually login and fix the stupid power management settings before trying to patch again but it was always a nasty surprise if you forgot about it and simply assumed MS wouldn't ever do something so braindead.