n the worst case scenarios, instead of loading the Mac OS X installer, you may end up at a dark gray screen that tells you to restart your computer (a kernel panic), or you may end up with a small crossed-out sign (a loading error). If you get a kernel panic/loading error (or if the Mac OS X installer simply won't start within 10 minutes), you'll need to enter some boot flags. To enter boot flags, manually restart your computer by pressing your computer's power button. Then, once you've booted back into the Niresh menu, try typing any necessary boot flags before pressing the enter/return key. Check out our list of common boot flags and our guide to fixing boot problems with verbose mode for reference.