After shutting down the computer, unplug the power and data cables from the hard disk where the system is installed, and plug it into another hard disk to install the system (if this hard disk is already plugged in with a cable to install the system directly, it is better to set this hard disk as the master disk). After installation, then connect the two hard disk cables (one of them should be set as a slave disk), and then set up in CMOS to choose which disk to start

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