MSI 945 Neo5 Series User Manual page 51

BIOS Setup
Boot Sequence
The original IBM PCs loaded the DOS operating system from drive A (floppy disk), so
IBM PC-compatible systems are designed to search for an operating system first on
drive A, and then on drive C (hard disk). However, modern computers usually load
the operating system from the hard drive, and may even load it from a CD-ROM drive.
1st Boot Device
The item allows you to set the sequence of boot devices where BIOS attempts to load
the disk operating system.
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