How to use a boot disk What is a boot disk and why do I need one? A boot disk is a floppy or a CD that you can use to boot your computer into a state in which you can use it to fix a problem.

You can make a bootable MS-DOS disk using the utilities built into Windows XP. Alternatively, you can create an image of the Windows XP files to use as a bootable disk.

Windows allows you to create multiple FAT32 and NTFS partitions on a USB or External drive using Diskpart, Disk Management, MakeWinPEMedia.

With it, you'll be able to use Safari to find troubleshooting information, run Disk Utility to fix filesystem errors, restore from a Time Machine backup, or install Mountain Lion from scratch on ...