Dell Dimension XPS 50 Reference Manual page 157

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Legacy Floppy The operating system assigns drive letters to removable
Drives devices in the order listed on the Removable Devices sub-
menu. To change the drive designations, reorder the list: Use
the up- or down-arrow key to highlight a device, and press
the plus (+) or minus (–) key to move the item up or down
the list.
NOTE: The Glossary in the system Help defines abbreviations and acronyms.
System Setup Program B-23