'備用'的翻譯不準確, 應該是選擇, 選 2G capacity when you can't use/freezes 6.4G]

When to use Alternate Jumper Settings
The most common scenario when a drive should be configured with the Alternate Jumper Settings is when the system hangs up or freezes upon boot up after auto-detecting all IDE devices. The reason for this error is because the drive capacity is larger than what the system can support.

http://wdc.custhelp.com/app/answers...jumper-settings