The boot drive is usually the first hard drive on the system, but may also be a diskette, CD, or USB key.

引动驱动器通常是系统上的第一个硬盘驱动器，但也可以是一个磁盘、CD 或 USB 密匙。

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You may normally boot from a hard drive, but you may sometimes need to boot from a floppy disk, a USB memory key, a CD or DVD, or a network.

您可能通常从硬盘驱动器引导，但有时可能需要从软盘、usb内存密匙、CD或DVD，或者网络引导。

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You can perform the preliminary boot steps from a supported device such as a floppy drive, CD, USB key, or a tiny partition on the main drive, and then use the external drive for everything else.

可以从支持的设备(如软盘驱动器、CD、USB key或主驱动器上的微小分区)执行初始引导步骤，然后使用外置驱动器进行其他操作。

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