Those errors typically pertain to a driver problem with the IDE controller. If the boot device [hard drive] is inaccessable, then obviously something in between the OS and the hard drive is ...

Some users have complained about this problem that when they start their computer, it doesn’t boot. Instead, a Default Boot Device Missing or Boot Failed blue ...

I've been running relatively stable for the last few months. Receive a notification this morning that windows needed to restart for an update. Figure it's something that downloaded in the background ...